Marcell Coetzee emerged as the chief tormentor of Ulster by blasting over for the crucial try against his old teammates as the Vodacom Bulls ran out 34-16 winners in Pretoria.
Ulster have signed former Leinster veteran, Michael Kearney, who joins the province from United Rugby Championship rivals Zebre.
It was January when Ulster thought they had pulled off a coup by signing Fijian talisman Leone Nakarawa from Glasgow for next season.
Tries from British and Irish Lions duo Jack Conan and Robbie Henshaw did the damage for Leinster in a hard-earned 21-17 win over Ulster at the RDS Arena.
It's a big semi-final weekend in Europe, with eight teams vying to make four spots across the two EPCR tournament finals after what has been a chaotic 14 months for the game.
Ulster fans have were left furious yesterday, not so much at the nature of the red card handed to prop Andy Warwick, but rather that previous Leinster infringements didn't warrant the same punishment.
Holders Leinster booked their place in the Guinness PRO14 final by securing a 38-19 bonus-point victory over their only challengers Ulster to ensure they now cannot be caught.
Leinster will get one foot in the door of the Guinness PRO14 final on March 27 if they can topple Ulster in the Kingspan on Saturday night.
Ulster triumphed 21-7 over the Ospreys at the Kingspan Stadium but failed to secure the bonus point that would have heaped maximum pressure on Conference A leaders Leinster.
