Mikkel Kessler

On 29 November 2002, Kessler fought for his first championship and defeated former WBC Super Middleweight Champion Dingaan Thobela over twelve rounds to become the International Boxing Association Champion. He gave up this belt to fight for the more recognized WBC International title on 11 April 2003, versus Craig Cummings. Kessler won by a knockout in the third round.

He defended his title on three occasions before finally hitting it big on 12 November 2004. His stablemate, Mads Larsen, another Danish World Class fighter, was set to challenge Manny Siaca for the WBA Championship in Copenhagen. Larsen was injured in training and Kessler took the fight on short notice, winning the title.

Kessler defended his title against Anthony Mundine in Sydney in June 2005 and Eric Lucas in January 2006.

On 14 October 2006, Kessler was elevated to WBA Super Champion status after winning the WBC title in a unification battle against WBC World Champion Markus Beyer at the Parken Stadium. He won by knockout at 2:58 in round 3.

Kessler defended his WBA (Super) and WBC titles on 24 March 2007, at the Parken Stadium against WBC mandatory challenger Librado Andrade. The fight was scored as a shutout (120–108) by all three judges.

Kessler then met fellow undefeated champion, Welshman Joe Calzaghe, in a bout that would unify his WBA and WBC super middleweight championships with Calzaghe's WBO and The Ring titles. The bout took place at Cardiff's Millennium Stadium on 3 November 2007, in front of over 50,000 fans (then the largest indoor boxing event in European history), and Kessler lost the unification bout via unanimous decision, with the judges scoring the fight: 117–111, 116–112, 116–112.

After Calzaghe vacated the WBA title to move up to light heavyweight, Kessler was put in a match with Dimitri Sartison on 21 June 2008, for the vacant belt. Kessler knocked out Sartison in the final round to regain his title.

Kessler successfully defended his title against Danilo Häussler by third-round knockout on 25 October and against Gusmyl Perdomo (16–2, 10KOs) by fourth-round knockout on 12 September 2009, one minute into the round.

In November 2009 the WBA once again promoted him to Super Champion, this time prior to unifying any Super Middleweight titles.

His first fight was against Andre Ward on 21 November 2009 for Kessler's WBA Super Middleweight Championship in the Super Six World Boxing Classic. On 21 November 2009 Kessler lost his championship to Andre Ward. The fight was stopped in the eleventh round due to cuts on Kessler's face caused by what were deemed as unintentional headbutts by Ward, five in total. Kessler expressed in the post fight interview that he couldn't get out of first gear due to the headbutts and excessive clinching from Ward, and that he was eventually blinded by one of Ward's headbutts which on the post fight replay showed Ward ram his forehead directly into Kessler's eye. The fight went to the scorecards and Ward was far ahead by scores of 98–92, 98–92 and 97–93 at the time of the stoppage.

On 24 April 2010 Kessler returned to fight against Britain's undefeated WBC Champion Carl Froch, a match that was called "a classic" and "one of the best matches in Danish boxing ever." The contest went the distance and Kessler was handed a unanimous decision with scores of 115–113, 116–112 and 117–111. With the win, Kessler became a two time WBC Champion, handing Carl Froch his first defeat in the process. Froch later stated that he'd suffered a minor ear injury during training and he felt he would've won the fight if it had been held in his home-country of England, but congratulated Kessler on his victory.

In 2012, Kessler moved up in weight class to light heavyweight. In May 2012, he fought Allan Green for the vacant WBC Silver Light Heavyweight title. Kessler won via knockout in the fourth round, after getting dropped by a hard right hand in the first round.

Late in 2012, Kessler went up against Brian Magee of Northern Ireland for the WBA Super middleweight title. Two times in the 2nd round Brian Magee went to the floor after hard bodyshots from Kessler, and 24 seconds in the third round it was all over, when Kessler landed another hard bodyshot to Brian Magee.

On 15 January 2013, it was announced that a rematch between Mikkel Kessler and Carl Froch was going to take place on 25 May 2013 at The O2 Arena in London. There will be two belts on the line, Kessler's WBA- and Froch's IBF title. Kessler won the last showdown between the two boxers, in Herning, Denmark. That time Froch was an undefeated WBC title holder, and they were both fighting in the Super Six World Boxing Classic. The faced each other at stage 2, after Kessler lost his first fight against Andre Ward, and Froch won a close fought contest against Andre Dirrell.

Froch defeated Kessler by unanimous decision on 25 May 2013, by 118-110 116-112 115-113 as he controlled Kessler with his jab for large parts of the fight. Kessler caught Froch with a big right hand in the 11th round to wobble him, but it was too late in the fight.

On 1 February 2015, Kessler announced that he was in a "state of retirement" via social media. Kessler came out of retirement on 31 March 2017. On 21 June, it was said that Kessler could be added to the World Boxing Super Series. Kessler passed on the Super Series and was looking to face Roamer Angulo on November. On 16 October, Kessler revealed he had been hit by Lyme disease and his return would be delayed until 2018. In February 2018, speaking to BT, Kessler said, "I just can't find the motivation to go through with it all," confirming he would stay retired.