Osman Diaz

Diaz was stopped in the second round by Ateba Gautier at UFC 328, unable to avoid an overhand right and follow-up hammerfists after surviving into round two.

Key moments

• Finished by strikes at 1:10 of round two.
• The loss dropped him to 10-4 overall.
• It was Gautier's fifth straight UFC win.

Diaz won his first UFC fight by going the distance against Djorden Santos at UFC 313, taking a unanimous decision over three rounds.

Key moments

• Won by unanimous decision after three full rounds.
• It was Diaz's first UFC win.
• The result also marked Santos's UFC debut.

Diaz's UFC debut in Macau ended early, stopped in the first round by Zhang Mingyang.

Key moments

• Lost by first-round TKO in his UFC debut.
• The bout was contested at light heavyweight before Diaz moved back to middleweight.
• UFC.com records the stoppage at 2:25 of round one.

Diaz stopped Bevon Lewis in the second round at LFA 184, part of the regional run that earned him his UFC contract.

Key moments

• Finished Lewis by TKO in round two.
• Extended his win streak heading into the UFC.
• Fought under the LFA banner.

Diaz knocked out Chuck Campbell in the first round at LFA 178, continuing his late-career finishing run on the regional circuit.

Key moments

• Finished Campbell by KO in round one.
• Part of a two-fight LFA finishing streak in early 2024.
• Fought at middleweight.

Diaz's first shot at a UFC contract ended when Joe Pyfer cracked him with a left hook and followed with ground-and-pound for the second-round stoppage on Contender Series. The loss mattered because it interrupted a strong regional rise, but it did not stop Diaz from rebuilding into an LFA titleholder and eventually reaching the UFC anyway.

Key moments

• Lost to Pyfer by second-round TKO at 1:39 on Contender Series.
• UFC and ESPN highlight coverage centered on the left hook that changed the fight.
• The defeat dropped Diaz to 7-2 before his later regional rebound.

Diaz answered the Pyfer setback in emphatic fashion by knocking out Bruno Assis late in the opening round of an LFA main event to win the vacant middleweight title. It was a statement result because it turned a would-be reset fight into championship hardware and put him right back on the prospect track.

Key moments

• Knocked out Assis at 4:53 of round one in the LFA 127 main event.
• Won the vacant LFA middleweight championship with the finish.
• The victory re-established Diaz as a title-level regional middleweight after DWCS.

Diaz claimed regional gold at LXF 6 by stopping Moses Murrietta in the second round, another fight where his pressure and power eventually broke the opponent. That win mattered because it gave him the LXF middleweight title and provided the momentum that carried him into the LFA championship picture.

Key moments

• Stopped Murrietta by second-round knockout at 1:54.
• The bout was for the LXF middleweight championship in Burbank.
• The win extended Diaz's finish-heavy streak on the California regional scene.

Diaz made quick work of Logan Woods at LFA 94, finishing him in under two minutes of the first round with punches. The result helped restart his upward push after the Bellator run and was one of the cleaner examples of how early Diaz can end a fight once he gets momentum.

Key moments

• Finished Woods by first-round TKO at 1:36.
• The bout took place on the LFA 94 card in Shawnee, Oklahoma.
• Combat Press and ESPN both recorded it as a short-notice early stoppage win.

Diaz showed a different part of his game at Bellator 228 by taking Andre Walker's back and finishing with a rear-naked choke in the opening round. That mattered because most of his résumé leans on knockouts, so the win reinforced that he could still close the door with grappling when the opportunity appeared.

Key moments

• Submitted Walker with a rear-naked choke at 3:05 of round one.
• The finish came on the Bellator 228 card in Inglewood.
• It gave Diaz his second Bellator win in 2019.

Diaz returned from the quick Fight Club OC loss by stopping Christopher Reyes late in the first round on the Bellator 214 undercard. It was an important rebound because it got him back to winning immediately on a bigger stage and kept his finishing identity intact.

Key moments

• Stopped Reyes with punches at 4:15 of round one.
• The bout took place on the Bellator 214 card in Los Angeles.
• It snapped Diaz's one-fight skid and started a two-fight Bellator winning stretch.

Diaz suffered the fastest loss of his professional career when Santiago Diaz stopped him fifteen seconds into their Fight Club OC 50 bout. The setback stands out because there was no time for his usual pressure game to develop, making it an abrupt interruption in the earliest stage of his pro climb.

Key moments

• Lost by TKO just 15 seconds into round one.
• The fight took place at Fight Club OC 50 in Southern California.
• It dropped Diaz to 2-1 as a professional before his later Bellator rebound.

Diaz banked another regional finish by stopping Saad Ul-Hasan in the second round at Fight Club OC. The win mattered as part of his early development because it showed the same attritional pattern that would define much of the rest of the record: heavy pressure first, then a punch finish once the fight opened up.

Key moments

• Stopped Ul-Hasan with punches at 1:54 of round two.
• The bout was held on a Fight Club OC card in December 2017.
• It pushed Diaz to 2-0 before his first setback two months later.

Diaz opened his professional career with a first-round rear-naked choke win over Leon Klee at KOTC: Sanctioned. It mattered as a debut because it established the finish-or-bust shape of the record immediately, even before his knockout count became the more obvious headline.

Key moments

• Won his pro debut by rear-naked choke at 2:31 of round one.
• The fight took place at KOTC: Sanctioned in June 2015.
• It remains one of the two submission wins on Diaz's professional résumé.