Mark Chamberlain stops Pierce O'Leary in 10th to claim IBO light-welterweight title

Mark Chamberlain produced a surprise victory over Pierce O'Leary in Dublin. He dropped O'Leary twice before finishing him with a 10th-round knockout to secure the IBO light-welterweight belt.

The contest featured Briton Mark Chamberlain against Republic of Ireland's Pierce O'Leary, with the outcome reported on 2026-08-01. Chamberlain entered the bout seeking a title opportunity while O'Leary fought on home soil in Dublin. The 10th-round stoppage determined the new IBO light-welterweight champion.

Chamberlain applied the decisive blows that forced two knockdowns during the fight, each contributing to the momentum that led to the conclusion in round 10. The second knockdown proved pivotal, as it preceded the finishing sequence that produced the knockout. The referee intervened following the final exchange to end the contest and award Chamberlain the win.

For O'Leary, the defeat came after being twice floored by his opponent, and the stoppage in the 10th round removed any chance of a late comeback. The result ended the bout decisively and handed the title to Chamberlain. The match outcome will be recorded as a 10th-round knockout for the British challenger.

Chamberlain's victory crowns him as the IBO light-welterweight champion following the knockout in Dublin. The sequence of two drops and the subsequent stoppage underscores the manner in which the title changed hands. The official result is a KO in the 10th round in favour of Mark Chamberlain.

The reporting of this result on 2026-08-01 confirms Chamberlain as the new holder of the IBO light-welterweight belt after his 10th-round knockout of Pierce O'Leary in Dublin. The win will stand in the records as a stoppage victory following two knockdowns earlier in the contest.