Britain's Dereck ''Del Boy'' Chisora will have his work cut out for him when he challenges one of the heavyweight division's all-time greats - defending WBC champion Vitali Klitschko - at the Olympiahalle in Munich, Germany on Saturday night. The affable Zimbabwe born Londoner is a massive 9/1 underdog [bet365] but because of his comparative youth [28 to Klitschko's 40], his burly physique and bustling, aggressive style, he is given an outside chance of pulling off a shock victory.

The Klitschko v Chisora WBC heavyweight title fight and its undercard will be shown live in the UK exclusively on BoxNation [Sky channel 456], the action starts at 8 PM.

Chisora proved in his most recent bout against WBO number one contender Robert Helenius in Finland last December that he can deal with an extremely tall opponent, something that he looked incapable of doing when he lost a one-sided decision in a British and Commonwealth heavyweight title fight to Tyson Fury last July. Although Chisora ultimately lost a split decision to Helenius, no one outside of Finland truly believes he was beaten.

The problem for Chisora is that at a shade over 6'1" and with a crouching, bobbing style, he will be right in the firing line of Klitschko's surface-to-air missiles. Unlike Helenius, who has a textbook – high guard, jab-cross style, the giant Ukrainian loves carrying his hands low and throwing his punches in an upward trajectory. This makes them harder to guard against, but less effective against an opponent who is as tall as he is. As Klitschko stands a fraction under 6'8", that has not happened too many times during his career, but interestingly the first man to take him the distance back in 2000 was the hulking 6'8" German Timo Hoffman.

Zimbabwe born Chisora [15-2, 9 KOs] is a former ABA super heavyweight champion who showed fight fans what he was capable of very early in his career, stopping fellow prospect and future Commonwealth champion Sam Sexton in six rounds in only his fifth pro bout. Chisora knocked out the vastly experienced former world title challenger Danny Williams for the British heavyweight title in 2010, and captured the Commonwealth belt later that year when he TKO'd Sexton in nine rounds in a rematch.

He was twice slated to face Wladimir Klitschko for his IBF/WBO belts in late 2010 and early 2011, but the first fight fell through when Wladimir tore an abdominal muscle, while the second was canceled when the then WBA champ David Haye agreed to take on Klitschko in a unification fight.

Chisora lost a little of his luster when he weighed in at a whopping 261 lbs for his fight with Tyson Fury last July and lost his championship belts somewhat tamely. Chisora possibly believed that the added bulk would result in him overpowering Fury early, but the only person the added weight hindered was himself.

Chisora vowed to bounce back following the Fury disaster, and was true to his word. He was a revelation in his fight against the dangerous, hard-hitting 6'6'' Helenius, 18 pounds lighter with extra speed, power and tremendous stamina. The huge Finn was the hottest heavyweight prospect in the world, with big KO wins over ex-world champs Siarhei Liakhovic and Samuel Peter. His straight right hand remains a potent weapon, similar to that of Liverpool's David Price, yet Chisora absorbed his best shots time and again and came back for more.

The Londoner's body attack was particularly ferocious and strength sapping, and he frequently sent sweat spraying from Helenius' head with his hooks and overhand rights.

Such is the improvement in Chisora, one would fancy his chances against most heavyweights in the world right now including Chris Arreola, Denis Boytsov, Tomasz Adamek and even David Haye. Because of WBA/WBO/IBF champ Wladimir Klitschko's more conventional style and natural caution, Chisora would have had a greater opportunity for success. Unfortunately, its Big Brother he's facing on Saturday.

There is an old adage in boxing that says great fighters that are performing well late in the their careers can suddenly ''grow old'' overnight. That may be the case with fighters who have cut corners throughout their careers and relied on their talent. However, the Klitschko brothers are different animals. They leave nothing to chance in their pre-fight preparation. They employ the best coaches and trainers, the best sparring partners, they stay in shape all year round and never miss a training session.

Although Vitali Klitschko [43-2, 40 KOs] is 40 years old, when one takes into account he had a four year sabbatical from the ring due to severe leg and back injuries and apart from his six round war with Lennox Lewis in 2003 he has never absorbed serious punishment, he is biologically only in his early 30's, a worrying prospect for the rest of the division.

This will be his twelfth title defence in three reigns as world champion [WBO champion from 1999-2000 and WBC champ from 2004-5 and 2008-201?]. He lost his WBO title to American Chris Byrd when he retired after nine rounds despite being a mile ahead on points. Labeled a quitter at the time, Klitschko believed that the shoulder injury he had sustained during the fight was so serious that it threatened his future career.

His only other loss came against Lennox Lewis in 2003. Despite absorbing some blockbuster right hands from the defending champion, Klitschko was ahead on points after six rounds, but had sustained a vicious cut above the eye. Lewis retained his WBC title but never boxed again.

Many regard George Foreman's return to boxing in 1987 after 10 years out of the ring and subsequent world title winning knockout over Michael Moorer seven years later as boxing's greatest ever comeback. However, I believe that Vitali Klitschko's return to the top after a four-year break due to extensive injuries, and subsequent dominance of the heavyweight division in his late 30s and beyond is THE greatest comeback of them all.

For Chisora to have a chance of defeating Vitali, he needs to come in in the shape of his life - at 240 lb or less - and focus on using his looping overhand right – an extremely effective punch against a taller opponent (check out Sergio Martinez' two round blitzkrieg of Paul Williams on YouTube for a great example, but remember Maravilla is a southpaw, so in his case it's an overhand left!)

The problem for Del Boy is that on top of all his other assets, Klitschko has a chin like the rock of Gibraltar. It will take more than one shot to finish him off, and we have seen time and again how effortlessly he leans away from punches and how difficult he is to tag.

I believe that Vitali's dominance of the heavyweight division continues on Saturday night. I see him timing his counters against the attacking Chisora to perfection. Few heavyweights in history have thrown as many punches per round as Klitschko, and few with more accuracy. Occasionally the champion displays genuine KO power, and but more often than not, it is the accumulative effect of his punches that does the damage.

By the eighth round, those punches will have taken a terrible toll on a brave but ultimately outclassed and outgunned Chisora, and the referee will come to his aid.

Klitschko by TKO in eight.

Big Fight Odds: Vitali Klitschko 1/16, Dereck Chisora 9/1 bet365