The Stormers suffered a heartbreaking last-minute defeat against Cardiff at the Arms Park after a late try from replacement prop Rhys Litterick handed the Welsh side a 31-24 victory.
The Bulls climbed to the top of the United Rugby Championship table after handing Cardiff a third defeat from four in an 18-12 win.
Connacht marked Andy Friend's final home game as their director of rugby with a 38-19 bonus-point win over Cardiff at the Sportsground.