Ulster 24 Cardiff 33:Ulster were beaten for the second time in a week by Cardiff last night in what was their fourth Magners League game without a win, a run which has seen bottom side Connacht close the gap on their provincial rivals to just four points.
The win keeps Cardiff's slim hopes of making the play-offs alive and bolsters their chances of staying in next season's Heineken Cup.
Tries from man of the match Casey Laulala, Ulster-bound Xavier Rush and replacement Dafydd Hewitt saw the Blues home, along with 14 points from the boot of Wales winger Leigh Halfpenny.
Ulster staged a second-half revival with scores from Stephen Ferris and Chris Henry, but they were never quite close enough to threaten Cardiff's control of the game.
Niall O'Connor got Ulster moving with an early penalty from under the posts when Gethin Jenkins was pinged at a five-metre scrum after David Pollock had been held up over the Blues line.
However, the remainder of the half belonged to the Blues, with O'Connor's place-kicking being Ulster's only response to two tries from the visitors.
Laulala's score came shortly after Ulster's opening penalty when a pass from O'Connor was picked off by the centre who ran in unopposed from 60 metres out. Ceri Sweeney converted the intercept and the Blues were on their way.
Halfpenny landed his first penalty nine minutes after Laulala's 10th-minute try and then just before the half-hour mark kicked a long-range effort after Ulster prop BJ Botha was penalised for dropping a scrum which put the Blues 10 points clear at 13-3.
A penalty from O'Connor at least kept Ulster in touch, but only briefly, as five minutes after the half hour Rush touched down under the posts when Isaac Boss failed to gather an up and under. The Blues, with space to burn, moved the ball at pace with Laulala providing the scoring pass.
Sweeney converted to make it 20-6 for the visitors and even though O'Connor kicked his third penalty it was Halfpenny who completed the half's scoring, with his third penalty putting the Blues 23-9 in front at the break.
O'Connor narrowed the Blues' lead to 23-12 shortly after the restart and then Ferris smashed over for an unconverted score eight minutes before the hour mark.
At 23-17 it looked as if Ulster might mount a realistic challenge but Halfpenny landed another penalty before just falling short from halfway.
Then, with 10 minutes remaining, replacement Hewitt danced past Botha after the Blues had kept the ball for about three minutes. Halfpenny converted.
Henry's try two minutes from time, which replacement Ian Humphreys converted, was mere consolation.