Ospreys picked up their first Anglo-Welsh Cup win of the season after thrashing 14-man Cardiff Blues 31-7 at the BT Sport Arms Park.
Blues prop Anton Peikrishvili was shown a red card following an altercation in the second half which turned the game on its head.
Tries from Rhodri Davies, Brendon Leonard, Tom O'Flaherty (two) and Dan Evans ensured Ospreys' bonus-point victory over their Welsh rivals. Both teams fielded relatively young sides for the Anglo-Welsh Cup clash, many of whom experienced their first real taste of regional rugby.
Newport Gwent Dragons secured derby bragging rights with a 36-21 victory against the Scarlets in the Anglo-Welsh Cup at Rodney Parade.
Tries by centre Sam Beard (2), lock Nick Crosswell, full-back Carl Meyer and flanker Harrison Keddie secured a bonus point success for the home side. The Scarlets led 16-10 at half-time but the match turned on a red card for flanker Jack Condy after an off-the-ball incident five minutes after the restart.
The west Wales side scored tries through hooker Dafydd Hughes and wing Corey Baldwin but were always up against it when reduced to 14.