Pierce O’Leary vs Mark Chamberlain Preview August 1st, 2026
Dublin, Ireland will be hosting a fine junior welterweight matchup this Saturday, August 1st as unbeaten hometown hero Pierce O’Leary takes on Mark Chamberlain of Portsmouth, England. The 12-rounder can be seen live on DAZN in most nations. O’Leary last fought in March when he stopped Maxi Hughes in the third round for the vacant IBO Junior Welterweight Title and that belt will be on the line this weekend. Chamberlain last saw action 12 months ago when he battled to a 10-round draw with Jack Rafferty in a shot at the British and Commonwealth Junior Welterweight Belts.
O’Leary vs Chamberlain Betting Odds
Here are the betting odds from online sportsbook BetOnline.ag (full review here).
- Mark Chamberlain +171
- Pierce O’Leary -225
My Pick
The 26-year-old O’Leary climbs into the ring with a perfect mark of 19-0 with 11 Ko’s and has 104 rounds of experience under his belt since making his pro debut in 2019. Before that he enjoyed an extensive amateur career after starting boxing at the age of seven and was reportedly a nine-time Irish amateur champion with 140 wins in 150 fights. He measures 5-feet-8-inches tall with a 68-inch reach. He has enough power to cause some damage as his current knockout ratio clocks in at 58 per cent and he’s halted nine of his last 13 opponents.
O’Leary won the vacant WBC International Junior Welterweight Title in 2022 with a 10-round unanimous decision over Emmanuel Mungandjela and defended it five times. He added the vacant European Title in June, 2025 via a 12-round unanimous decision over Liam Dillon and also has wins over Darragh Foley, Hovhannes Martirosyan, Robin Zamora and Kane Gardner. O’Leary is a good pressure fighter with a fine left hook and explosive combination-punching ability.
The 27-year-old Chamberlain is a southpaw who makes the ring walk with a mark of 17-1-1 with 12 Ko’s. He made his pro debut in 2018 and has boxed 91 rounds since. He also had a fine amateur career as he captured the 2018 English National Amateur Elite Lightweight Championship. Chamberlain is 5-feet-9-inches tall with an unlisted reach so has an inch edge in height over O’Leary. As far as power is concerned he has the edge in that department as well as 70.6 per cent of his wins have come by stoppage. He’s gone the distance in his last three fights though with a record of 1-1-1. Before that he had halted five opponents in a row.
Chamberlain captured the vacant IBF European Lightweight Title in 2022 with a 10-round unanimous decision over Marc Vidal and defended it three times. He halted Gavin Gwynne in the fourth round in 2024 for the WBA Intercontinental Lightweight Belt and added the vacant WBC Silver Lightweight Title the same year when he stopped Joshua Oluwaseun Wahab in 162 seconds. His lone defeat came at the hands of Josh Padley by 10-round unanimous decision in 2024 when he was dropped in the eighth round and had a point deducted for pushing in the ninth stanza.
Prediction…
Chamberlain has more power in his arsenal but is fighting in O’Leary’s backyard. They both have good skills and are more or less European and domestic-level boxers. This could go either way and a draw is a distinct possibility too. Whoever takes the bull by the horns and is the aggressor will have the edge here and it’s still hard to pick a winner. I’ll go with O’Leary because he’s unbeaten and fighting at home.
A tossup with O’Leary fighting in Dublin.
Play O’Leary -225 @ BetOnline.ag
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Mark Chamberlain betting • Pierce O'Leary betting