Wales fly-half Dan Biggar stole the show as Ospreys sent Cardiff Blues crashing to a 31-23 Guinness PRO12 defeat at the Millennium Stadium.
Biggar's sizzling attack and sturdy defence helped the Ospreys come back from a 9-0 deficit to seal a bonus-point win that keeps the pressure on Munster for third place in the play-off race.
The stand-off scored a try and kicked 11 points with a penalty and four conversions as full-back Dan Evans, wing Tom Grabham and centre Ben John scored Ospreys' other tries.
The Blues relied on a try from number eight Josh Navidi plus four Gareth Anscombe penalties, a late Dan Fish 80-metre interception try and conversions from Anscombe and Gareth Davies for their points.
It all started well for the Blues as the deadly boot of Anscombe made the Ospreys pay for conceding penalties within kickable range as he shot over twice in the opening 20 minutes to put the Blues six points clear.
But Ospreys could have scored two tries in that period when an outstanding leap from John from the restart, after Anscombe's first penalty success, saw him feed wing Eli Walker.
It was only an extraordinary cover tackle from Blues centre Tom Issacs 10 metres from the left corner that saved the day as Walker was pushed into touch.
And a more clear-cut chance came when the West Walians attacked in the Blues 22. Scrum-half Rhys Webb fed centre Josh Matavesi who passed onto number eight Dan Baker to go over. However, on video replay, Matavesi had slightly knocked-on and the touchdown was ruled out.
That sparked the Blues into life and, after Biggar put in a last-gasp tackle to stop centre Garyn Smith from scoring, the Cardiff region went nine points up with Anscombe's third penalty as Ospreys strayed offside.
Ospreys hit back just before half-time when Biggar kept up his exceptional first-half to evade Blues tackles and help set a ruck inside the Cardiff 22 that saw Baker feed prop Nicky Smith and, in turn, the front row sent Evans over in the corner, with the Ospreys fly-half converting
And Ospreys seized the initiative after the break when they ran into a 12-point lead as the Blues defence buckled.
British and Irish Lion Alun-Wyn Jones scythed past weak defence on half-way before laying the ball to Biggar to surge over.
Then Grabham finished off a superb move across the backs to receive a scoring pass from Evans on the right wing.
Biggar converted both but the Blues would not lay down and, when Navidi saw a gap between opposition hooker Scott Baldwin and Walker, he raced through gap to crash under the posts and make the conversion simple.
It was, though, a temporary lull for Ospreys as a first Biggar penalty of the day was followed by the best try of the match.
It suitably earned Ospreys the four-try bonus point as John started and finished a move that began on his 22, went through several hands before flanker Justin Tipuric sent the ball to his centre to run around from the right and go under the posts.
A forward pass denied Walker of a try at the end but it would have just been the icing on the cake of a 14th league victory in 20 games for the men from the West.
Fish's interception try, that Anscombe converted at the end, was mere consolation.