A bonus point win for Scarlets over Treviso on Saturday night saw Ulster slip out of the Guiness PRO12’s top four.
A 51-5 home demolitoin of Treviso saw Scarlets moved level on points with Ulster, but have won more games and take over fourth place.
Ulster drew 24-24 with Cardiff Blues at Kingspan Stadium on Friday night, having to come from behind four times to share the spoils.
But in what was their penultimate home game of the regular league season, they had missed a golden opportunity to move into third place.
Ospreys remin in third in spite of a 20-18 home defeat to league leaders Leinster on Saturday afternoon, although Dan Biggar, on his 200th appearance, missed a penalty in added time to snatch a win.
Ulster had won six successive games to dislodge Scarlets from fourth place and boost their chances of reaching the Championship play-offs.
But an error strewn display from Ulster - consistent with their form this season - saw them digging deep to at least take two points from the game.
Ulster go to second placed Munster in Limerick on Saturday knowing they must win to keep their chances of making the top four alive.
Munster’s 10-7 win over Glasgow last night saw them move seven points clear of Ospreys and both they and Leinster are a win away from securing their top four spot.
Ulster still have to tavel to Ospreys as well as face Leinster at home on the final day of the regular season, wtih Scarlets also taking on Ospreys on May 6.
Tha final day could still see three clubs battling it out for the last two play-off spots