Casey O'Neill's Long Road Back: From a Shattered Knee to UFC 331

When Casey O'Neill stopped Gabriella Fernandes inside a round in Seattle this past March, the screaming lap around the Octagon looked over the top. It wasn't. That win was her first appearance since a unanimous decision over Luana Santos in August 2024 — and it came after she tore every ligament in her right knee and broke her tibia during a routine wrestling drill.

Doctors floated the possibility she might never fight again. So blowing through the then-ranked Fernandes — an 11-4 flyweight with three knockouts of her own — wasn't just a result. O'Neill has called it maybe her best performance ever, delivered off a year and a half of doubt. This weekend she runs it back for a second time in 2026, facing #13-ranked Eduarda Moura at UFC 331.

A Prospect Interrupted

The UFC signed O'Neill as an undefeated 23-year-old and she looked the part fast: three stoppages plus a decision over veteran Roxanne Modafferi carried her into the top 10. Then everything tangled. A first knee injury cost her a year, and on the way back she dropped a decision to Jennifer Maia (23-10-1) before Ariane Da Silva submitted her nine months later. Gym changes followed — Xtreme Couture to Fight Ready — then another long layoff, then the knee that nearly ended it.

O'Neill says the injuries stripped away the identity she'd built around being a fighter, and forced her to figure out who she was without it. The reset came in Thailand. She never meant to leave Bangtao Muay Thai & MMA in the first place — a COVID-era stint in Las Vegas is how she got signed — and she describes stepping off the plane back into that gym as a wave of peace. It's where she started her pro career broke, and where the hunger came back.

Timing Is Everything

She's a couple weeks shy of 29, and she frames the lost years not as a waste but as a delay that let her mature — 22-year-old Casey, she admits, thought she was more ready than she was. Now she talks about peaking, the way fighters tend to around 29 or 30, and she wants to stop moving sideways in the rankings.

Moura sits one spot below O'Neill after dropping a unanimous decision to impending title challenger Wang Cong, but her 12-2 record and five submission wins make her exactly the kind of ranked name O'Neill asked for. The message this time is simpler than survival: she's done fighting stagnant, and she wants to climb.