[1] Cleverly made his professional debut in July 2005 with a four-round victory over journeyman Ernie Smith at the Meadowbank Sports Center in Edinburgh and within a year had compiled a winning ledger of 6–0.

The fight which was on the undercard to the match up between Joe Calzaghe and Sakio Bika ended in a 5th round stoppage for Cleverly and handed Quigley his first pro defeat.

The next big test for the young prospect took place at the Millennium Stadium in Cardiff just over a year later in September 2007 when Cleverly met tough Ugandan Joey Vegas.

Cleverly, fighting outside the UK for the first time as a pro also faced American opposition and beat Antonio Baker over 8 rounds.

Cleverly had been concerned following the legal wranglings between promoter Frank Warren and his former stablemate Joe Calzaghe and added "I cannot take any chances with my career ...

"[4] "I have worked hard for this but this is just the start for me – I want to rule the world" In October 2008, Cleverly landed a shot at the vacant Commonwealth light heavyweight title topping the bill for the first time in his career at the Everton Park Sports Centre in Liverpool.

[8] The victory over Boyle set Cleverly up for a shot at the vacant British title on 18 July 2009 against English champion Danny McIntosh.

[9] Following the victory Cleverly laid claim to being the best light heavyweight in Britain, despite the fact that fellow Brit Clinton Woods was soon to be travelling to Florida in a challenge for the vacant IBF World title against Tavoris Cloud.

[13] "As well as crunching numbers, I've had to fight for the British, Commonwealth and European titles as well, and spend most evenings hitting the heavy bag and doing numerous press ups and sit ups" On 13 February 2010 Cleverly took on Antonio Brancalion at Wembley Arena in a bid to gain the vacant European light-heavyweight title.

"[15] On 18 September 2010 Cleverly faced the unbeaten Karo Murat at the LG Arena in Birmingham in an eliminator for the WBO light heavyweight title.

Murat, a former European champion at super middleweight, struggled to match the Welshman after an explosive start and after being rocked in the 9th, the referee decided to stop the fight prior to the commencement of the 10th.

[16] Cleverly earned the interim version of the belt on 11 December 2010 in an unimpressive contest with the Frenchman Nadjib Mohammedi at the Echo Arena in Liverpool.

"[17] Cleverly had fought for the interim title as the full champion Jürgen Brähmer was in the midst of an appeal against a 16-month jail sentence for assault and insulting behaviour.

[17] An appeal heard in Germany on 13 December 2010 would, if Brähmer had been unsuccessful and sent to prison, have resulted in the belt being vacated and Cleverly being upgraded to the full champion status.

"[18] Prior to the fight at The O2 Arena in London, Brähmer pulled out citing an eye injury received in training which had failed to heal properly.

The pullout resulted in the loss of the main event for the show and speculation that Cleverly would be awarded the full WBO title by default.

Bellew, however, failed to make the weight and a second replacement was found in Polish veteran Aleksy Kuziemski, a man ranked at number 11 in the world by the WBO.

[20] Cleverly made his first defence of his WBO title on 15 October 2011 with a hard-fought majority points decision against Tony Bellew in Liverpool.

[21] Warren announced on 3 January 3, 2012, that Cleverly would return to Wales to make a defence of his WBO title against 25 year old American contender Tommy Karpency (21–2–1, 14 KOs).

[24][25][26] On 5 November 2012, Cleverly traveled to the United States to make a third title defence against American boxer Shawn Hawk (23–2–1, 17 KOs) at the Staples Center in Los Angeles.

[27] Cleverly was originally scheduled to defend his title against Ryan Coyne, but the fight was called off due to contract disputes involving infamous promoter Don King.

As referee Tony Crebs stepped in to halt the fight, Hawk's corner also threw in the towel, to avoid their man receiving any more punishment.

[30][31][32] On 20 December 2012, it was announced that Cleverly world make a defence of his WBO title against mandatory challenger Robin Krasniqi (39–2, 15 KOs) on 16 March 2013.

[29][33][34] In what was supposed to be Cleverly's toughest fight to date, he out skilled and out pointed Krasniqi winning by unanimous decision at the Wembley Arena on 20 April 2013.

[35][36] Cleverly made his fifth defence of the title against undefeated Russian Sergey Kovalev (21–0–1, 19 KOs) on 17 August 2013 at the Motorpoint Arena in Cardiff.

Fonfara outlasted Cleverly over 12 entertaining rounds to claim a victory by unanimous decision in the main event of a Premier Boxing Champions card.

[47] On 22 July 2016 it was announced on Sky Sports that Cleverly would finally meet his long-standing rival Jürgen Brähmer (48–2, 35 KOs) for the WBA 'Regular' light-heavyweight title on 1 October at the Jahnsportforum in Mecklenburg-Vorpommern in Germany.

[48] On the night, Cleverly became a two-time world champion at light heavyweight, after Braehmer retired on his stool with an injured elbow at the end of the 6th round, which his promoter later confirmed was dislocated.

A day after the fight, there was already dispute between both camps as to where the rematch would be held, with promoter Eddie Hearn claiming Cleverly should have the home advantage.

[52][53][54] After Badou Jack (21–1–2, 12 KOs) moved up to light heavyweight, on 19 June 2017, he revealed that his team were working towards a deal for him to fight Cleverly.