Ulster caught out by Cardiff's late show
Cardiff Blues 23 Ulster 13
Ulster director of rugby Les Kiss has urged his men to recover from their Cardiff capitulation by hunting down Zebre next week.
Ulster looked to have reignited their Pro12 title challenge with 10 minutes to go after a Craig Gilroy try and eight Paddy Jackson points had them 13-9 in-front.
But Rhys Patchell and Aled Summerhill found gaps in the tiring defence to derail Ulster's title challenge late on.
"It's disappointing, we had a good chat at the end of the game and we know we are not in the best form at the moment," said Kiss. "We have to stay real, we're still up the top of the ladder, we have to arrest this, because we know it's an important game for us to make sure we stay in the hunt next week."
Shortly after half-time, with the scores tied at 6-6, centre Sam Arnold led the Ulster charge after a quick-tap penalty and burst through before finding Gilroy on the overlap, who waltzed home for the converted score.
Stuart Olding kept his side in-front when he made a try-saving tackle on Dan Fish after Patchell had broken clear.
The Blues kicker converted a penalty to pull the Blues back within four points and Ulster's defence finally gave way when Samoa international Rey Lee-Lo burst through and found Patchell to put the Blues in-front.
And the result was put beyond doubt when Sumerhill touched down in the corner.
Cardiff Blues - D Fish (J Evans 60); B Scully, A Summerhill, R Lee-Lo, T James; R Patchell, T Williams (L Jones 66); B Thyer (T Davies 75), M Rees (K Dacey 68), S Ma'afu (T Filise 40); J Hoeata, J Down; J Turnbull, E Jenkins, M Vosawai (J Navidi 62).
Ulster - S Olding; C Gilroy, L Marshall (D Cave 6), S Arnold (R Scholes 71), J Stockdale; P Jackson (capt), R Pienaar; C Black (K McCall 49), J Andrews, B Ross (R Lutton 40); P Browne (R Wilson 66), F van der Merwe ; R Diack, C Henry (S Reidy 56), N Williams.
Ref - John Lacey (IRFU)