Mark Chamberlain produced a dramatic tenth-round stoppage of Pierce O’Leary to win the IBO world super-lightweight title at Dublin’s 3Arena.

The challenger dropped O’Leary twice during a commanding start, survived a determined response and then found the decisive finish during the closing stages of an absorbing main event.

O’Leary recovered from knockdowns in the second and third rounds to hurt Chamberlain with a body shot in the seventh. However, the Waterlooville fighter regained control and ended the contest with a powerful combination in round 10.

The result gave Chamberlain the biggest victory of his professional career and ended O’Leary’s unbeaten record during the Dublin fighter’s first defence of the title. Chamberlain improved to 18 wins, one defeat and one draw, with 13 stoppages, while O’Leary fell to 19-1.

Chamberlain Makes a Blistering Start

The atmosphere inside the 3Arena belonged firmly to O’Leary, but Chamberlain refused to allow the occasion to dictate the opening rounds.

His southpaw stance and distance control caused immediate problems. O’Leary struggled to move inside safely, while Chamberlain repeatedly found a home for his straight left hand.

The challenger made the first major breakthrough late in the second round. A left hand sent O’Leary to the canvas and left the defending champion bleeding heavily from the nose.

O’Leary returned to his corner under significant pressure, yet his problems continued in the third. Chamberlain attacked with greater confidence and scored a second knockdown with a short punch at close range.

At that stage, the contest appeared to be slipping away from the champion. Chamberlain had established a considerable advantage and had also demonstrated that his power remained effective after moving into the 140lb division.

O’Leary Fights His Way Back

O’Leary could easily have become more reckless after such a damaging start. Instead, he gradually found a way back into the fight.

He increased the pressure from the fourth round, forcing Chamberlain towards the ropes and beginning to target the challenger’s body. Although the damage to O’Leary’s nose remained visible, his work became more controlled and effective.

Chamberlain continued to threaten with counters, but his output dropped as O’Leary closed the distance more consistently.

The momentum shifted sharply in the seventh round. O’Leary trapped Chamberlain near the corner and landed a heavy body shot that sent the challenger down.

Chamberlain returned to his feet and was helped by the round ending shortly afterwards. Nevertheless, the knockdown transformed the mood inside the arena and gave O’Leary renewed belief.

The defending champion continued to move forward in the eighth and ninth rounds. Chamberlain was forced to absorb sustained pressure, while O’Leary appeared increasingly confident that he could complete an unlikely recovery.

The fight had developed into a battle of composure as much as power. Chamberlain needed to rediscover the timing that had brought him early success, while O’Leary had to maintain his pressure without leaving himself exposed.

Chamberlain Finds the Finish

The contest ended suddenly during round 10.

O’Leary again pushed Chamberlain towards the ropes, but the challenger responded with a forceful combination. A right uppercut began the attack before further punches drove O’Leary backwards and left the referee with little choice but to intervene.

The finish completed a composed performance from Chamberlain. He had dominated the early rounds, endured O’Leary’s recovery and retained enough power to stop the champion when another opportunity appeared.

It also delivered the title opportunity that Chamberlain had originally expected to receive in March. Illness forced him to withdraw from the first scheduled meeting, leaving O’Leary to face Maxi Hughes for the vacant championship.

O’Leary stopped Hughes after five rounds to become champion, setting up Saturday’s delayed contest.

World in Sport’s No Turning Back Dublin preview outlined the contrasting pressures facing the pair before their eventual meeting.

Chamberlain’s victory changes their respective positions within the super-lightweight division. He leaves Dublin as the IBO champion, while O’Leary must rebuild after suffering the first defeat of his professional career.

The quality of O’Leary’s resistance should not be overlooked. He recovered from two early knockdowns, fought through a badly damaged nose and came close to changing the contest after dropping Chamberlain.

However, the night ultimately belonged to a challenger who handled the hostile surroundings and produced the cleaner finishing sequence when the fight remained delicately balanced.

Barney-Smith Controls Experienced Bellotti

Royston Barney-Smith extended his unbeaten record with a wide unanimous-decision victory over Reece Bellotti in the chief supporting contest.

The 22-year-old used his movement, speed and southpaw right hook to prevent Bellotti from applying sustained pressure. Bellotti continued to move forward, but he struggled to close the distance without being caught by straight left hands and quick combinations.

All three judges awarded the fight to Barney-Smith, returning scores of 100-90, 99-91 and 98-92.

The victory took Barney-Smith’s professional record to 17-0 and represented another important step against an opponent with extensive British and Commonwealth title experience.

Cully Stops Reeves in Final Round

Gary Cully defeated Lee Reeves with a dramatic stoppage during the tenth and final round of their all-Irish super-lightweight contest.

Reeves had provided Cully with a demanding test and remained competitive deep into the fight. Cully eventually found the breakthrough with less than a minute remaining, ending the contest before the scorecards were required.

Reeves was taken to hospital following the bout. No detailed medical update had been confirmed at the time of publication.

Cully’s victory improved his record to 20-2 and marked his second consecutive win since losing to Maxi Hughes in December 2024.

Cairns and Fail Secure Fifth-Round Stoppages

Steven Cairns remained unbeaten after stopping Senan Kelly in the fifth round.

Cairns controlled much of the contest through his movement and accurate counter-punching. A clash of heads left him with a cut above his left eye in the fourth. But he responded by dropping Kelly with a left hook early in the following round.

Kelly regained his feet, although the referee intervened when Cairns continued his attack. The victory moved Cairns to 15-0 with 10 stoppages.

Ben Fail also recorded a fifth-round victory, knocking out Craig O’Brien with a well-timed left hand near the end of the session.

O’Brien attempted to frustrate the taller southpaw by moving around the ring and attacking in short bursts. Fail maintained his pressure, worked consistently to the body and ended the contest with a single clean shot.

Fail is now unbeaten in 12 professional appearances.

Olaniyan and Flood Continue Unbeaten Starts

Irish heavyweight Adam Olaniyan claimed the third stoppage victory of his professional career by defeating late replacement Deepak Pathak in the second round.

Olaniyan controlled the contest with his jab and repeatedly landed to the head and body. A lead right hand dropped Pathak early in round two, with the referee stopping the fight after the British-based boxer returned to his feet.

The 20-year-old, who won gold at the 2024 World Youth Championships, improved to 3-0. He is scheduled to return on the undercard of Katie Taylor’s farewell fight at Croke Park on 5 September.

Bobbi Flood moved to 3-0 by stopping Tariq Davis in the fourth round. John Joe Carrigan maintained his perfect stoppage record with a third-round victory over Sean Murray.

Sean McComb outpointed Miguel Cesario Antin over six rounds, Machlan Arthur stopped Ryan Frost in the fourth and Sami Hamed defeated Bela Istvan Orban on points in his professional debut.

Full No Turning Back Dublin Results

The complete card delivered victories for several emerging prospects, but Chamberlain’s success carried the greatest immediate consequence.

Having waited for his opportunity and travelled into O’Leary’s home city, he left the 3Arena with the IBO championship after a contest that tested his power, resilience and judgement.

Further reports and analysis are available through World in Sport’s boxing coverage.