Pierce O’Leary has suffered a 10th-round knock-out defeat in his IBO World super lightweight championship title defence against England’s Mark Chamberlain at the Three Arena in Dublin.

Chamberlain, who pulled out of a scheduled showdown between the pair in March due to a chest infection, caught previously-unbeaten O’Leary on the ropes with a numbing combination before the referee stepped in to stop the fight.

The 27-year-old Englishman silenced O’Leary’s fans at the 3Arena as the Dubliner crashed to his first professional defeat.

O’Leary, bidding for a 20th straight professional win, was floored by a left to the nose in the second round and again by another left in the third before recovering his composure to take the fight to his opponent.

DUBLIN, IRELAND - AUGUST 1: Pierce O'Leary (green shorts) in action versus Mark Chamberlain (white shorts) during the Pierce O'Leary v Mark Chamberlain fight night at The 3Arena Dublin on August 1, 2026 in Dublin, Ireland. (Photo by Charles McQuillan/Getty Images)
O’Leary and Chamberlain put on a show in Dublin

The Dubliner appeared to have turned the tide when a vicious body shot sent Chamberlain to the canvas in the seventh and he kept coming forward as an epic contest unfolded.

But after being backed into a corner in the 10th, Chamberlain stepped off the ropes and caught O’Leary with a flurry of bruising punches that sent him down for a third time and there was no way back.

“First and foremost, respect to Pierce, massive thank you to Queensbury, Frank, and Piece for giving me this opportunity,2 Chamberlain said.

“I’m not a stranger to an away day, and anyone that knows me deep down knows I will fight anyone, anywhere.

“If means I’ve got to go in the champions back garden, I’ll do that.

“But I take my hat off to Pierce because he’s a true champion and he’ll come again.”