Title challenges vs. Edwards and Haskins

McDonnell's first fight outside his home town saw him travel to the York Hall in London to defeat Nikita Lukin on 21 September 2007 in an eight-round fight. His next fight was to be for the British super-flyweight title at the Robin Park Centre in Wigan on 8 December 2007. The fight with Chris Edwards would be the first time the British super-flyweight had been contested making this the inaugural contest for the belt. The experienced Edwards eventually won the title via split decision after twelve hotly contested rounds handing a first defeat for the Doncaster man.^[3]

On 28 March 2008 McDonnell suffered his second defeat in a row having travelled to Barnsley to meet Lee Haskins. The fight with Haskins resulted in another close loss over eight rounds with Haskins himself coming off a British title loss to Ian Napa in the bantamweight division. The fight in Barnsley doubled as an eliminator for the winner to challenge for the super-flyweight title which Haskins would go on to win.^[4]

British bantamweight champion

Following two straight defeats to British level fighters, McDonnell regrouped by returning to m and beating journeyman Anthony Hanna via fifth-round stoppage. Two fights on the island of Jersey then followed with McDonnell scoring stoppage wins over imports Krastan Krastanov and Alain Bonnel before travelling back to Doncaster to defeat James Ancliff again before the final bell had been heard. On 22 January 2010 McDonnell got his chance to fight for the British title once again, this time for the bantamweight version held by the experienced Ian Napa. The fight, at the Brentwood Centre in Essex, saw a tough battle result in an upset split decision win for McDonnell with the added bonus of the vacant Commonwealth bantamweight title also being on the line.^[5]

European bantamweight champion

McDonnell's victory over Napa allowed him to step straight into a challenge for the European title against the Jerome Arnould. The fight, in Cannes on 20 March 2010, resulted in a surprise victory for the man from Doncaster with a tenth-round stoppage over Arnould to lift his third title in a row.^[6] McDonnell made his first defence at the Doncaster Dome on 2 July 2010 against the newly crowned Italian champion Rodrigo Bracco and managed to retain the belt with a third-round stoppage win.^[7] He returned to the Dome for his second defence on 22 January 2011 beating Stephane Jamoye in a close contest with scores of 115–113 114–113 114–114 despite having a point deducted in the eleventh round.^[8] McDonnell chose to defend the Commonwealth belt he won against Ian Napa in his next fight in Sheffield on 28 May 2011. Had he lost the contest McDonnell would have been stripped of his European title but there were no such concerns as he scored a unanimous decision victory over Nick Otieno. Following the fight, promoter Frank Maloney said that a potential unification match with British champion Stuart Hall could be on the cards and that it was a fight that both the fans and the boxers themselves wanted to happen. Mcdonnell fought Hall on 3 September 2011 and won via unanimous decision to reclaim the British title.^[9]

WBA bantamweight champion

On 31 May 2014 McDonnell fought Tamadang Da Rachawat for the WBA (Regular) bantamweight title on the undercard of Carl Froch vs. George Groves II at Wembley Stadium. McDonnell won by technical knockout when he caught Rachawat with a left hook in the tenth round; despite getting to his feet, the referee decided that Rachawat was in no state to continue as he visibly stumbled after getting up.

His first title defense was on 22 November 2014 at the Echo Arena in Liverpool. McDonnell retained his title, defeating Javier Chacon via tenth-round knockout.^[10]

His next title defense was also his US debut, against Japanese boxer Tomoki Kameda, in which McDonnell was considered the underdog despite holding the title. Things were going Kameda's way in the early rounds, and he even managed to drop McDonnell in the third round. In the fifth round, things would start going McDonnell's way. All three judges thought McDonnell's performance in the latter part of the fight was enough, with all three scoring the fight 114–113 in favor of the Brit.^[11]

In the rematch, Kameda again started off strong, being the more active fighter during the first two rounds. McDonnell would then take control of most of the remainder of the fight, boxing intelligently and managing to drop Kameda in the closing round. This time, the Brit was the clear winner, winning the fight 117–110, 116–111 and 115–112 on the scorecards.^[12]

McDonnell next faced Fernando Vargas, as a late replacement for Juan Alberto Rosas. McDonnell used his high work rate and jab to establish control during the fight, dropping Vargas in the ninth round before the referee waved the fight off.^[13]

On 12 November 2016 McDonnell faced the WBA's #2 ranked bantamweight, Liborio Solis. It would prove to be a very tough fight for McDonnell, who got the win on the scorecards, despite many at ringside, along with the Sky Sports pundits, having Solis winning the fight.^[14]

On 1 February 2017 the WBA officially ordered a rematch between the two.^[15]

The rematch ended in a third-round no-contest after McDonnell suffered a cut below his left eye following an accidental clash of heads.^[16]

On 25 May 2018 McDonnell faced Naoya Inoue at the Ota City General Gymnasium in Tokyo, Japan. Inoue was simply too good for the visiting fighter, managing to drop him twice in the first two minutes of the fight, forcing the referee to wave it off.^[17]

Shorltly after his loss, McDonnell announced that he will be moving up in weight.^[18]

On 11 May 2021, McDonnell announced his retirement from boxing via post on his Instagram account.^[19]