Blood Diamond Record: 3-5-0

UFC tenure

Mathetha's UFC run proved difficult. He debuted at UFC 271 in February 2022 against Jeremiah Wells, who submitted him by first-round rear-naked choke. He rebounded into a competitive but losing effort at UFC 277 in July 2022, dropping a unanimous decision to Orion Cosce after the pair's bout had twice been scrapped earlier in the year. His final Octagon appearance came at UFC 293 in September 2023, where he lost a unanimous decision to Charles Radtke. The promotional stint, while winless, came against the kind of seasoned competition that exposed the gap between elite kickboxing and the full MMA skill set.

After the UFC

Released from the UFC, Mathetha returned to the regional circuit. He suffered a first-round knockout loss to Raymart Quintana at HEX Fight Series 30 in May 2024 and a unanimous-decision defeat to Jack James at Beatdown Promotions 10 in March 2025, leaving his MMA record at 3–5.

Fighting style

Blood Diamond is, at his core, a striker – a product of City Kickboxing's renowned standup program and his own deep amateur and professional kickboxing background. His MMA finishes split evenly between a knockout and a submission, and his offense is built on the crisp boxing and kicking that made him a champion on the feet. The record also lays bare the holes that derailed his UFC run: three of his five MMA losses came by decision and the other two by knockout and submission, signaling vulnerabilities in his grappling defense and an inability to consistently impose his striking against grappling-savvy opponents at the highest level. He remains a dangerous finisher when he can keep a fight standing.

Career highlights

• Two-time King in the Ring champion — twice won New Zealand's premier kickboxing tournament, a feat shared with UFC veteran Dan Hooker.
• City Kickboxing-backed UFC signing — earned a UFC contract in 2021 out of the same Auckland gym as champion Israel Adesanya, reaching the sport's biggest stage.
• Over 100 striking bouts — built a reported kickboxing tally of more than 100 fights with a single loss before crossing over to mixed martial arts.