Cardiff: Cam Winnett; Josh Adams, Louie Hennessey, Ben Thomas (capt), Gabriel Hamer-Webb, Callum Sheedy, Ellis Bevan; Danny Southworth, Evan Lloyd, Kieron Assiratti, Seb Davies, Teddy Williams, James Botham, Dan Thomas, Alun Lawrence.
Replacements: Daf Hughes, Corey Domachowski, Rhys Litterick, Josh McNally, Thomas Young, Taulupe Faletau, Aled Davies, Rory Jennings.
Sin bin: Williams (49), Litterick (68)
Ospreys: Max Nagy; Iestyn Hopkins, Owen Watkin, Keiran Williams, Keelan Giles; Dan Edwards, Reuben Morgan-Williams; Gareth Thomas, Sam Parry, Tom Botha, Rhys Davies, James Fender, Jac Morgan (capt), Justin Tipuric, Morgan Morris
Replacements: Lewis Lloyd, Garyn Phillips, Rhys Henry, James Ratti, Morgan Morse, Kieran Hardy, Jack Walsh, Evardi Boshoff.
Red card: Fender (39)
Referee: Ben Breakspear (WRU)
Assistant referees: Ben Connor &Adam Jones (WRU)
TMO: Tom Spurrier (WRU)