Boxing's no.1 superstar Manny Pacquiao defends his WBO world welterweight title for the third time when he takes on another modern ring legend in Mexico's Juan Manuel Marquez at the MGM Grand in Las Vegas on Saturday night. It will be the third meeting between these two - the first in 2004 ended in a draw, and Pacquiao won a split decision in their 2008 rematch. 

Marquez is the current WBA/WBO lightweight champion, and is the one fighter to have consistently given Pacquiao nightmares during his illustrious 16 year career. 

While it would seem that the 2011 model Pacquiao (53-3-2, 38 KOs) will be simply too big and hit too hard for the 38-year-old Marquez, the Mexican has employed one of the best strength and conditioning  coaches in the business – Angel Hernandez - to pack on the quality muscle necessary to go head-to-head with 32 year old Pacman at welterweight. 

Although the Filipino is rightly regarded as the best offensive fighter on the planet, Marquez is the best counterpuncher in boxing. It all adds up to an intriguing blend of fighting styles and past history that makes Pacquiao Marquez III a must see for millions of fight fans around the world.

No matter what happens in Las Vegas on Saturday, Juan Manuel Marquez's (53-5-1, 39 KOs) place in the boxing Hall of Fame and his position of as one of Mexico's greatest ever fighters is secure. 

Marquez turned professional way back in 1993 after compiling a 35-1amateur career that included two Golden Gloves titles. His pro career got off to an inauspicious start when he lost his first fight on an opening round disqualification, but Marquez was soon into his stride, and would go unbeaten in 29 bouts over the next six years.

His winning streak was snapped in 1999 when he dropped a 12 round decision to American Freddie Norwood in a shot at Norwood's WBA featherweight title. Marquez would put together another unbeaten run of almost seven years before losing again.

He won the WBA featherweight title with a seventh round stoppage over Manuel Medina in February 2003 - his first world crown. It was during his reign as featherweight champion that he first faced Manny Pacquiao. Pacquiao at that point was himself a former two-weight world champion, and by then under the tutelage of master trainer Freddie Roach. 

Had the three knockdown rule been in place, the Pacquiao Marquez rivalry would never have happened, as within the first 3 minutes of the fight, Pacquiao's ferocious assault had sent Marquez to the canvass three times. 

Few men in boxing history have ever recovered from such a disastrous start, and it speaks volumes for Marquez both as a man and a fighter that he did not only recover, but stormed back to wage war from the second round onward, and after 12 sensational stanzas, appeared to have done enough to take the decision.

The official announcement was a draw. The champion had retained his title and the Pacquiao Marquez rivalry had been born.

Marquez would ultimately lose his featherweight title to Indonesia's Chris John in 2006, but he would not remain an ex-champion for long; In 2007 he relieved fellow Mexican modern great Marco Antonio Barrera of his WBC super featherweight title, and it was this belt that was up for grabs when Marquez defended against Pacquiao for a second time.

At the Mandalay Bay Resort and Casino in Las Vegas in March 2008, fight fans were once again treated to a sensational encounter. Again Marquez was to hit the canvas, but only once this time - in round three. The bout was a virtual carbon copy of their first encounter, and after 12 exhilarating rounds, many at ringside and millions more watching on TV around the world thought that Marquez had done enough to retain his title. However, this time the Mexican was left devastated when the split verdict and the WBC super featherweight title were awarded to Pacquiao.

By now Marquez was 35 years old - retirement age for most fighters, but this amazing Mexican wasn't quite done yet. Reinventing himself as a lightweight, he scored a superb 11th round KO over former two-time world champion and Olympic gold medalist Joel Casamayor of Cuba, before taking on fearsome punching fellow Mexican Juan Diaz for the vacant WBO and WBA lightweight titles in February 2009.

In arguably the most exciting fight of Marquez's career, he took an incredible pounding from an opponent ten years his junior, but rallied to TKO Diaz in the ninth round and become a three-weight world champion.

In September 2009 Marquez took a big money catch-weight bout against Floyd Mayweather Jr. It was his first foray into the  welterweight division, although in reality, he was still very much a lightweight. Although he scaled 142 pounds at the weigh-in, he looked small and slight against Mayweather in the ring.

The fight itself was a dud. Matching a defensive fighter like Mayweather against a counterpuncher like Marquez was hardly an astute piece of matchmaking. Marquez was forced to be the aggressor, and although Mayweather floored his man in the second round with a perfect straight right, the Mexican was never in trouble again. Marquez lost the fight on a landslide decision in what was the biggest payday of his career so far. 

Dropping back down to lightweight, Marquez proved that he could box as well as slug when he outsmarted Juan Diaz for a comfortable decision in their 2010 rematch. Next came his pier-six-brawl against Michael Katsidis last November. Once again, Marquez absorbed many heavy shots and hit the canvas in the third round, but proved his incredible resilience to overcome the courageous Aussie in the ninth round.

Last time out in July, a 138 lb Marquez blew away Colombian Likar Ramos in one round. He has been working with controversial strength coach Angel Hernandez (infamous for supplying disgraced former Olympic champion Marion Jones with steroids) to build quality muscle on his is 5'7" frame.  

Marquez's tenure as a lightweight has been precarious yet impressive. He should have lost to Juan Diaz but found a way to win. Michael Katsidis looked to be riding the momentum going into their title fight and floored the Mexican with what he would later say were the hardest shots he had taken in his career. Yet it was to be Marquez's pinpoint accurate counterpunches that would undo the Aussie's challenge, ultimately ending when Marquez stopped him in round nine.

Like Rocky Balboa, Marquez seems to improve with the more wars he is in. Just when you think his number must surely must be up, he comes storming back with another great victory. He is looking to come in at a rock-hard 144 lbs on Saturday. Even if that doesn't equate to more punching power (aside from Pacquiao, few fighters actually gain punching power when they climb the divisions) it should aid in his physical strength and shock absorption. 

Being able to absorb blunt force trauma is requisite for any fighter with illusions of defeating the Ferocious Filipino Manny Pacquiao. Few fighters in history have thrown as many hard punches per-round in their fights as Pacman, who's right jab alone carries bone breaking power. (It was his jab that broke the cheekbone of Antonio Margarito last November.)

Throughout history, many great fighters have climbed the divisions, but few have actually added to their punching power. The late great Nicaraguan Alexis Arguello carried his knockout power from junior lightweight up to junior welterweight. James Toney won the IBF middleweight title in 1991, and became one of only two men to stop four-time heavyweight champion Evander Holyfield in 2003. 

Arguello and Toney are the exception – the rule is that a fighter who is a devastating puncher in one division will see his power depreciate as he climbs the weights, the prime example being Roberto Duran.  

A fearsome puncher at lightweight - capable of knocking a man cold in the first or the fifteenth round, Duran was less effective but still dangerous at welterweight, and found it harder to put quality opponents away as he moved up to light middleweight, middleweight and eventually super middleweight. 

Of course Duran was such a great fighter technically, he was able to claim world titles in four separate weight classes, but only at lightweight was he a truly devastating puncher. 

Not so Manny Pacquiao. The Filipino claimed his first world title way back in 1998 with an eighth round knockout over Chatchai Sasakul for the WBC flyweight title when he was just 19 years old. Back then, all of Pacquiao's fights seemed to end in knockouts, including two when he was on the receiving end. If one searches YouTube they can still find images of Pacquiao being iced in three rounds by Rustico Torrecampo in 1996, and losing his flyweight crown when he is stopped in the third round by Medgoen Singsurat in 1999.

Close scrutiny of Pacquiao's ascension through the weight divisions reveals there is no letup in the amount of knockouts he churns out. He picked up his second world title, the IBF super bantamweight championship with a sixth round knockout over South African Lehlohonolo Ledwaba in 2001. 

As the years have rolled on, Pacquiao's increasing punching power has enabled him to stop the great Marco Antonio Barrera at featherweight (TKO 11), knock out Erik Morales in three rounds at super featherweight, demolish David Diaz for the WBC lightweight title (TKO 9), starch Ricky Hatton in two rounds at junior welterweight and bludgeon seasoned welterweights Oscar De La Hoya and Miguel Cotto to defeat inside the distance (TKO'd in nine and twelve rounds respectively.) 

He may have gone the distance in his last three fights, but that is more down to the resilience of the opposition rather than a decline in his punching power. Ghanaian Joshua Clottey has never been stopped in his career, and employed a high guard and very little offense while surviving 12 one-sided rounds against Pacquiao at the Cowboys Stadium in Texas in March 2010. Antonio Margarito went a long way to redeeming his tarnished reputation by displaying astonishing bravery, absorbing a savage pummeling but lasting the distance against Pacquiao last November.

Three weight world champion Shane Mosley has never previously come close to suffering an inside the distance defeat, yet was taking such a bad beating he wanted to quit on his stool in the latter rounds of his bout against Pacquiao in May. 

In his frequent criticism of Pacquiao, Floyd Mayweather Jr desperately clings to two points which he believes to be so significant that he raises them time and time again: A) Pacquiao has been KO'd during his career, and B) that Pacquiao's rise through the weight classes must be down to some kind of performance enhancing drugs.

What Floyd always fails to mention is that when both he and Pacquiao were aged 16, they were both light flyweights. Because of the abject poverty his family were living in, Pacquiao turned pro at that young age. Two years earlier, a 16-year-old Floyd Mayweather had won the 1993 National Golden gloves light flyweight title.

In this writer's opinion, Pacquiao's desperately poor background meant that he was suffering the aftereffects of malnutrition during the first few years of his professional boxing career, and as a result was fighting in weight classes far lighter than he would have been had he had a more healthy upbringing. 

I also believe that this is the prime reason (allied to his then kamikaze fighting style) as to why Pacquiao suffered those two early career knockout losses. Does anybody truly believe that Torrecampo and Singsurat hit harder than Barrera, Morales, Marquez, De La Hoya, Hatton, Cotto, Margarito and Mosely? 

Unfortunately for Marquez, there is pretty much nothing wrong with Manny Pacquiao's chin. If anything, the amount of heavy blows he took flush on the jaw in his 12 round victory over Margarito last year proved just how great a chin he truly has.

So how can Juan Manuel Marquez defeat Manny Pacquiao on Saturday night? 

The one difference between this fight and all other previous fights that Pacquiao has prepared for, is that for this fight he seems to be genuinely angry, and wants to punish Marquez. In 2010, Marquez turned up at post fight press conference wearing a T-shirt emblazoned with the words ''I beat Manny Pacquiao twice''. 

Supposedly this has riled Pacquiao, and he is training with even more intensity and venom than normal (if that were possible). 

Whether this is just hype is not clear. If Pacquiao really does have a genuine personal beef with Marquez, it could affect his discipline in the ring. Pacquiao normally has a Zen like quality that sees him go into a fight smiling and relaxed - before proceeding to deliver the mother-of-all beatings on his opponent. If he were to fight with fury, it could leave him wide open to those laser-guided counterpunches that Marquez specializes in. 

It is clear that certainly at featherweight and super featherweight, Marquez knows how to fight Pacquiao. He is the perfect matador to the Filipino's bull. The problem for Marquez is that the welterweight version of Pacquiao is a whole new animal. Sure, there will be little difference in the Filipinos fighting style from 2008 to now, but in terms of size, strength and power, Pacquiao is a proven, full-blown 147 pound fighting machine. Marquez on the other hand was boxing as a lightweight as recently as last November.

One must ask themselves the simple question: does Manny Pacquiao punch harder than Juan Diaz and Michael Katsidis? Surely the answer is yes. Is he a better boxer that Diaz or Katsidis? Again the answer is yes. Worryingly, both Diaz and Katsidis came within a punch or two of becoming the first fighter to stop Marquez.

What Diaz and Katsidis came close to achieving, Pacquiao will achieve. I predict that Marquez will make the fight competitive and sting Pacquiao with hard counters in the early rounds that will earn the champions respect.

But at 38 years old and after the career he has had, Marquez's speed, reflexes and punch-resistance will be sufficiently diminished, and he will be taking severe punishment by the middle rounds. We all saw the damage that sustained blows delivered by Pacquiao to the human head can do last November when he turned Margarito's face into that of a gargoyle.

Marquez is one of the bravest men to ever enter a ring. He truly believes that he will win on Saturday, and will fight accordingly – above and beyond the call of duty. 

However, I believe by the ninth round he will be taking a savage pounding, and because of this I truly hope that either his corner or the referee will see sense and save him before he suffers serious damage. 

Pacquiao by TKO in nine rounds. 

Big Fight Odds: Manny Pacquiao 1/12, Juan Manuel Marquez 6/1 bet365