It was the 14th league win for Cardiff, but Newbridge put up a brave show and led 17-12 at one point.
Cardiff tries came from forwards James Goode (2), Chris Purcell and James Malpas with a penalty try and other touchdowns from backs Leon Andrews, Richard Jones and Liam Roberts. Andrews converted one and replacement Chris Anderson goaled six.
Newbridge, with several new faces, scored tries by wing Mark Addis and forwards Leighton Davies, Tom Lampard and Stuart Coles with a conversions each by fly half Ross Watts and full back Ross Jones.
Tonight (Wed) Bedwas entertain Pontypridd (7.15pm) with the return at Sardis Road on Saturday.
WRU International Skills Coach Jason Strange is a busy man, combining the new role with that of Wales Under 20 attack coach, Ebbw Vale head coach and continuing to teach at Ebbw Fawr Learning Community.
Warren Gatland and Sam Warburton look ahead to this week's crunch RBS 6 Nations tie against France, where the Wales skipper in particular is keen to make his mark, as Paris has proved a bleak place for him in the past.
Following their historic win over England, Wales Under 20 suffered a narrow, 36-34 loss to their Scottish counterparts last weekend, despite outscoring them by five tries to three. Watch the match highlights and reaction.
WRU TV go behind the scenes with the Wales squad as they put the final touches in place ahead of the clash against Scotland at Murrayfield. Follow the squad on their captain's run, the kickers visit to Murrayfield and Neil Jenkins' press conference