A dramatic late try by Paul Marshall secured Ulster a 23-23 draw against Munster to set up next weekend’s decider over who will host the Guinness PRO12 semi-finals.
Replacement scrum-half Marshall touched down in injury-time, with Paddy Jackson converting in the last minute.
Tommy Bowe's try towards the end of the first half saw 14-man Ulster recover from nine points down to lead 10-9.
Iain Henderson was sent-off with six minutes remaining and a Keith Earls try appeared to have won the game for Munster.
The result sees Munster join the Ospreys and Glasgow at the top of the Pro12 table on 70 points, with Ulster a point behind in fourth.
Connacht sealed a 40-10 bonus-point win over Zebre with six tries, boosting their chances of playing in the European Champions Cup next season.
John Cooney scored two first-half tries as Connacht led 21-10 at the break.
Eoghan Masterson ran in the fourth try after 54 minutes to secure the bonus point for the visitors.
Connacht need to beat Pro12 leaders Ospreys in the final game next week to fight for a top-six finish.
Leinster defeated Treviso 10-0 to qualify for the European Champions Cup despite an unconvincing Pro12 performance at the RDS.
On a night when the home fans paid tribute to the retiring Shane Jennings and Gordon D'Arcy, Leinster struggled to see off second-from-bottom Treviso.
Jamie Heaslip's eighth-minute converted try was the only score of an uneventful first half in Dublin.
Treviso's Edoardo Gori was red-carded for a dangerous tackle on D’Arcy before a 77th-minute penalty from Jimmy Gopperth sealed the win.