When the Queensberry Promotions banner rises over Dublin’s 3Arena this weekend on Saturday, August 1, 2026, the atmosphere will carry the heavy weight of delayed promises. Pierce O’Leary (19-0, 11 KOs) and Mark Chamberlain (17-1-1, 12 KOs) were originally scheduled to square off in March, only for a sudden illness to force Chamberlain out of the card. While that disruption allowed the 26-year-old Irishman to captivate a sold-out hometown crowd with a fifth-round knockout of Maxi Hughes to claim the vacant IBO world super lightweight belt, it left an unfinished narrative in the 140-pound division. Now under the banner of a card aptly titled No Turning Back, the rescheduled pairing is finally realized, pitting a surging champion against a dangerous English southpaw.
The tactical identity of this matchup is forged by two fighters who notoriously refuse to take a backward step. O’Leary, nicknamed 'Big Bang', enters with an unblemished professional record built since his 2019 debut and nine Irish titles, backed by a relentless, aggressive style that electrified Dublin earlier this year. Promoter Frank Warren noted the undeniable chemistry of the pairing, observing, It is one of those fights where you just know it will deliver. Two young talents, big punchers who don’t take a backward step. All the ingredients are there for a real barnstormer, with a world title on top this time.
Across the canvas stands 27-year-old Chamberlain from Waterlooville, stepping into only his second major assignment at super lightweight. Formerly a lightweight titleholder boasting belts including the WBC Silver, WBA Intercontinental, and IBF European straps, Chamberlain carries a formidable 71% knockout rate—outpacing O'Leary's 58% clip. In his previous venture north to Altrincham, Chamberlain endured a brutal, non-stop 12-round war against undefeated Jack Rafferty for the British and Commonwealth titles that ended in a split draw. Armed with southpaw angles and heavy hands, Chamberlain is eager to erase the lingering frustration of his prior withdrawal and claim the IBO strap on enemy soil.
The Undercard and Spatial Depth in Dublin
Beyond the main event, the 3Arena card features a deep rotational mix of domestic clashes and rising prospects designed to showcase the ongoing revival of professional boxing in Dublin. The chief support bout pits unbeaten prospect Royston Barney-Smith (16-0, 8 KOs) against seasoned veteran Reece Bellotti (20-7, 15 KOs) for the vacant IBO Inter-Continental Super Featherweight title over 10 rounds.
Local fans will also bear witness to fierce domestic rivalries down the card:
- Gary Cully (19-2, 10 KOs) vs. Lee Reeves (16-1, 11 KOs) – A 10-round all-Irish super lightweight encounter.
- Steven Cairns (14-0, 9 KOs) vs. Senan Kelly (12-1, 2 KOs) – Another high-stakes domestic 10-round super lightweight showdown.
- Ben Fail (11-0, 6 KOs) vs. Craig O’Brien (15-4, 2 KOs) – A compelling super welterweight battle.
- Adam Olaniyan (2-0, 2 KOs) vs. Jonathan Claudio Sauco – Heavyweight action following Olaniyan's recent Dublin debut.
Additional pairings feature Sean McComb meeting Miguel Cesario Antin at super lightweight, Bobbi Flood battling Tariq Davis at super welterweight, Machlan Arthur facing Ryan Frost at welterweight, alongside John Joe Carrigan against Sean Murray and Sami Hamed versus Bela Istvan Orban.
Viewing Logistics and Broadcast Details
Global broadcast rights for the event are held exclusively by DAZN, ensuring the entire card—from early undercard bouts starting at 7:00 PM local time up to the main event ringwalks expected between 10:00 PM and 10:30 PM—is streamed live. Standard DAZN subscriptions start at €15.99 monthly with varying commitments, while Amazon Prime Video subscribers can access the broadcast via the platform's dedicated DAZN channel for €25.99. Traditional sports broadcasters such as Sky Sports and TNT Sports will not carry the event.
Sources
These sources formed the evidence pack for this article. Links open the original publisher; inclusion does not imply endorsement.
- Jake Hackney original
- NoSmokeBoxing original
- dazn.com original
- Jake Hackney original
- Marc Abrams original
- globalboxingnews.co.uk original
- Tim Rickson on 29th April 2026. original