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Kill The Body

and the head will die

Mark Chamberlain vs Pierce O'Leary — record, stats and common opponents compared

🇬🇧UNITED KINGDOM

Mark Chamberlain

🇮🇪IRELAND

Pierce O'Leary

Mark Chamberlain (18-1-1) and Pierce O'Leary (19-1) are compared on record, finishing method, activity, and common opponents on Kill The Body. The two have met once. They share no common opponents in Kill The Body's bout data.

Chamberlain

18

Wins13 KO · 72%

1

Loss

1

Draw20 tracked bouts

O'Leary

19

Wins11 KO · 58%

1

Loss

0

Draws20 tracked bouts

Head to Head

Chamberlain leads 1–0

Mark Chamberlain and Pierce O'Leary have met 1 time; Chamberlain leads 1–0.

Mark Chamberlain and Pierce O'Leary have met 1 time; Chamberlain leads 1–0.
Met2026Aug 1Series
Mark ChamberlainFighter AWWon1–0W–L
Pierce O'LearyFighter BLLost0–1W–L
ResultTKOR101Meeting

The Numbers

Chamberlain 4 · O'Leary 3 of 7 measurable rows
ChamberlainO'Leary
Record
18-1-119-1 (edge)
Win %0–100%
92.5%
95% (edge)
Wins by knockoutmax 13
13 (edge)
11
KO rate0–100%
72.22% (edge)
57.89%
Stoppage rate (tracked wins)†0–100%
72% (edge)
58%
Times stopped†max 1
0 (edge)
1
Title reignslevelmax 0
0
0
Bouts per year‡max 2.9
2.6
2.9 (edge)
Bouts trackedlevelmax 20
20
20

† Counted from bouts Kill The Body has ingested, not a career total. · ‡ Across each fighter's tracked career span. · Bars are scaled per row — percentages on 0–100, counts against the larger of the two. Every figure is also printed as text.

Tale of the Tape

Heightnot held
Mark Chamberlain: No height on file
Pierce O'Leary: 5′8″
Age1 yr apart
Mark Chamberlain: 27
Pierce O'Leary: 26
Stance
Mark Chamberlain: Southpaw
Pierce O'Leary: Orthodox

Mark Chamberlain left, Pierce O'Leary right, as everywhere on this page. Age is stated, not scored — neither age nor stance carries an edge.

How They Win

Tracked bouts only
Mark Chamberlain18 wins · from 20 tracked bouts

Mark Chamberlain: 18 tracked wins — 13 by KO/TKO (72%) and 5 on the cards (28%). Counted from 20 bouts Kill The Body has ingested.

13 by KO/TKO 72%5 on the cards 28%

Pierce O'Leary19 wins · from 20 tracked bouts

Pierce O'Leary: 19 tracked wins — 11 by KO/TKO (58%) and 8 on the cards (42%). Counted from 20 bouts Kill The Body has ingested.

11 by KO/TKO 58%8 on the cards 42%

One square per tracked win. Counted from the bouts Kill The Body has ingested for each fighter — Mark Chamberlain 20, Pierce O'Leary 20 — not from a career-complete method table.

Common Opponents

No opponents in common across the bouts Kill The Body has tracked for these two.

Current Form

Oldest left · newest right

Mark Chamberlain has won once since a draw with Jack Rafferty. Chamberlain last boxed on Aug 1, 2026 — 77 days ago.WLWDW

Wahab May 2024Padley Sep 2024Scaringi Apr 2025Rafferty Aug 2025O'Leary Aug 20262.6 tracked bouts per year

Pierce O'Leary had won four in a row before losing by stoppage to Mark Chamberlain. O'Leary last boxed on Aug 1, 2026 — 77 days ago.WWWWL

Perdomo Dec 2024Dillon Jun 2025Ronner Dec 2025Hughes Mar 2026Chamberlain Aug 20262.9 tracked bouts per year

Common Questions

With the rows behind them
Have Mark Chamberlain and Pierce O'Leary ever fought each other?
Yes. Mark Chamberlain and Pierce O'Leary met once on August 1, 2026, and Mark Chamberlain won by TKO in round 10.
The meeting

WAug 1, 2026 · Chamberlain · TKO R10

Head to Head ↓
Who has the better record, Chamberlain or O'Leary?
Mark Chamberlain is 18-1-1 and Pierce O'Leary is 19-1. Pierce O'Leary has the higher win percentage.
Records · win %

Chamberlain18–1–192.5%

O'Leary19–195%

The Numbers ↓
Who has more knockouts, Chamberlain or O'Leary?
Mark Chamberlain has 13 knockout wins and Pierce O'Leary has 11. Mark Chamberlain has more.
Knockout wins · KO rate

Chamberlain1372.2%

O'Leary1157.9%

The Numbers ↓
Do Chamberlain and O'Leary have any common opponents?
Kill The Body's bout data shows no opponents that both Mark Chamberlain and Pierce O'Leary have faced.
How much fight data does Kill The Body have on Chamberlain and O'Leary?
This comparison is drawn from 20 bouts tracked for Mark Chamberlain and 20 bouts tracked for Pierce O'Leary. Method and activity splits reflect those bouts only.
Bouts tracked · no edge

Chamberlain20bouts

O'Leary20bouts

How They Win ↓

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