Despite missing a whole host of Welsh Test stars, the Blues recorded their first away victory in the RaboDirect PRO12 since October.
First-half tries from Martyn Williams and Harry Robinson put the Blues in control at the Stadio di Monigo, with seven points from the boot of Dan Parks effectively ensuring the game was as good as won before the interval.
Veteran openside Williams crossed on the half-hour mark after impressive work from full back Chris Czekaj and scrum-half Richie Rees.
Parks converted from out wide as the Blues finally earned their reward for their early dominance having seen Cory Hill, Ceri Sweeney and Czekaj all go close.
Young Wales squad member Robinson then made it two tries in as many minutes for the Blues as he supplied an assured finish from long distance after Parks had picked off an interception inside his own half.
Parks added the extras and then went on to slot a second penalty after the break following a yellow card to Treviso flanker Manoa Vosawai and the Blues never looked like letting their 20-3 lead slip.
And although the final scoreline suggested a tight encounter, in reality this was a comfortable win for the visitors as both Treviso’s tries came in the final seven minutes.
Simon Picone and Brendan Williams crossed for the Italians on 73 and 78 minutes, with Willem de Waal’s conversion of the second score securing Treviso a losing bonus point.
The result sees the Blues stay in seventh in the standings but they are now just five points behind the second-placed Ospreys with a game in hand.
