Casey O'Neill Submits Eduarda Moura with Armbar in Round 1 at UFC 331

Casey O'Neill extended her winning streak to three fights with a stunning first-round armbar submission of Eduarda Moura at UFC 331 on September 19, turning a defensive position into a fight-ending finish.

The sequence told the story of the bout in miniature. Moura spent roughly three minutes controlling O'Neill from top position and was pursuing a choke of her own when O'Neill, working off her back, isolated the arm and forced the tapout. The win moves O'Neill to 12-2, her best run in the sport to date.

O'Neill, 28, competes in the women's flyweight division out of Xtreme Couture and carries a ranked position in the top fifteen. The Scottish fighter is one of the more offensively active strikers in the division, averaging 7.89 significant strikes per minute at 52 percent accuracy. Her grappling output rounds out a well-balanced skillset, and Saturday's finish demonstrated a willingness to work submissions from disadvantaged positions.

Moura, 32, entered the bout ranked just one spot below O'Neill at No. 13 in the flyweight standings and brought a formidable grappling resume of her own. The Brazilian, who trains out of Galpao da Luta, averages 3.58 takedowns per 15 minutes — a rate that reflects the top-control pressure she applied for much of the opening round. Her record falls to 12-3, and the Moura suffered her second consecutive defeat and, notably, her first career stoppage loss.

Why it matters

• O'Neill's third straight win at 12-2 strengthens her case for a higher divisional ranking in a competitive flyweight picture.
• Moura's back-to-back losses and first career stoppage defeat raise questions about her trajectory at 32 years old.
• The finish itself — an armbar from bottom position — underscores O'Neill's submission threat even when opponents win the wrestling exchange.