Munster nosed ahead of Ulster for the first time in the 74th minute tonight and survived a late scare to take victory in Ravenhill.
Rory Scannell's drop goal delivered a 15-14 win for Munster.
By that stage, the Ulster crowd felt they should have been more a converted drop goal ahead of their opponents. Darren Sweetnam was penalised on the 68th minute allowing Paddy Jackson a decent penalty chance.
It was from roughly the same position as Johnny Sexton's late penalty against New Zealand three years ago.
However, just as Jackson was about to swipe the ball off the kicking tee, a firework went off outside the ground. He pushed the kick wide and the crowd oohed and aahed disapprovingly.
Paddy jogged back to his mark smiling slightly.
A firework goes off outside the ground the very second Paddy Jackson goes to connect with that penalty. Bloody Halloween
— Cahair O'Kane (@CahairOKane1) October 28, 2016
Would love to meet whoever set a firework off when Paddy Jackson took his penalty tonight ??
— Ian (@petergriffdog) October 28, 2016
Very unfortunate timing of a firework going off in the background as Jackson was about to strike penalty attempt! Score stays ULS 14-12 MUN.
— Ulster Rugby (@UlsterRugby) October 28, 2016
Six minutes later, the Munster forwards pounded against the Ulster defence, working their way into the 22. The ball was slipped back to Scannell who booted the ball between the sticks. It's Munster third successive win in Ravenhill.