Ruan Pienaar clinched the victory for Ulster Rugby in an exciting showdown at Ravenhill with Munster which ended 29-19.
The South African both opened and closed the cracking Irish derby with penalties, putting the first points on the board three minutes in.
Ulster had the upper hand in the first half, with superb tries from Jared Payne and Darren Cave.
But they allowed Munster back in just before the half-time whistle blew,with an Ivan Dineen touchdown, which the visitors failed to convert, taking the scoreline to 20-5.
Pro12 leaders Munster launched a fight-back in the second half with two more tries from loosehead Dave Kilcoyne and number 8 James Coughlan to make the Ulster fans sweat.
But they were left to rue a string of missed kicks by fly-half Ian Keatle.
Three penalties from Man of the Match Pienaar, one right at the death, secured the crucial victory for a relieved Ulster and achieved the points they needed.
The men in white were made to work for the win, in what was probably the best game of the season so far.
ULSTER (20) 29
Tries: Payne, Cave Cons: Peinaar 2 Pens: Peinaar 5
MUNSTER (5) 19
Tries: Dineen, Kilcoyne, Coughlan Cons: Keatley 2