Mark Chamberlain stopped Pierce O’Leary in the tenth round at 3Arena in Dublin to win the IBO junior welterweight title on Saturday. The British contender dropped the previously undefeated Irish champion three times overall to secure a dramatic stoppage victory.
Mark Chamberlain produced a career-defining performance in Dublin, knocking down Pierce O’Leary early with a left hand in the second round before scoring another knockdown with a short left hook in the third.
O’Leary mounted a fierce mid-fight comeback, applying relentless pressure to pull himself back into contention. The Irish champion trapped Chamberlain in a corner during the seventh round, delivering a severe body shot that sent the challenger to the canvas. Chamberlain rose slowly to survive the round, as O’Leary continued to press forward.
The decisive breakthrough arrived in the tenth round. Chamberlain landed a sharp combination that forced O’Leary to drop his guard, followed by a clean straight right hand that sent the champion into the ropes and down. The referee immediately waved off the contest, handing O’Leary the first defeat of his professional career.
The victory completes an important recovery for Chamberlain, who had previously suffered his first professional loss in 2024 before drawing with Jack Rafferty. For O’Leary, the result ended his reign in his very first defense of the title he had won against Maxi Hughes.
On the undercard, Royston Barney-Smith secured the vacant IBO Intercontinental junior lightweight title while retaining his WBO European belt with a ten-round unanimous decision over veteran Reece Bellotti. The 22-year-old southpaw relied on swift movement, sharp timing, and precise counter-punching. Although Bellotti found success when pinning Barney-Smith against the ropes, the younger fighter controlled the action to earn scores of 100-90, 99-91, and 98-92.
Gary Cully closed the main card with a dramatic single-punch knockout of Lee Reeves in an all-Irish junior welterweight encounter. Despite losing a point in the fifth round due to persistent gumshield issues, Cully landed a perfectly timed left hand 53 seconds into the final round that knocked Reeves unconscious. Reeves was taken to a local hospital as a precaution.
Afterward, Cully praised Reeves for forcing a grueling contest and noted that moving up to junior welterweight has revitalized his career after previously competing at lightweight. Chamberlain, Barney-Smith, and Cully now move forward with heightened momentum in their respective divisions.
