Cardiff secured the opening Welsh derby of the United Rugby Championship season with a convincing 21-15 victory over Scarlets in Llanelli. The visitors dominated through effective attacking play, particularly from driving line-outs, which yielded tries from flanker Dan Thomas, player-of-the-match Taine Basham and replacement hooker Evan Lloyd. Scarlets mounted a competitive first-half performance with tries from centre Joe Roberts and full-back Blair Murray, but failed to sustain their challenge in the second half. The result is significant given Cardiff's stronger league position—sixth-placed finishers last season and the only Welsh team in last season's play-offs—compared to a struggling Scarlets side currently languishing fourteenth in the United Rugby Championship.

Both teams were depleted by injuries, with Cardiff missing Wales wing Josh Adams but handing debuts to summer signings Scott Sio and Le Roux Malan, whilst Scarlets were without Wales fly-half Sam Costelow and injured number eights Fletcher Anderson and Taine Plumtree. The match took place before 7,073 spectators at an inconvenient 7:45pm Saturday evening kick-off. Scarlets centre Eddie James proved an impressive performer for the hosts, demonstrating both power and finesse in ball-carrying, though his individual efforts proved insufficient. Cardiff's bench proved crucial in sealing victory, with replacements including Wales flanker James Botham helping to secure a disciplined second-half defensive display.