Ulster avoided two successive defeats to Irish rivals by becoming only the third side to get the better of PRO12 leaders Munster this season as they bagged a vital 29-19 victory to move back into the top four.
And with two weekends of defining Heineken Cup action now ahead – Ulster are top of Pool Five and the only unbeaten side in Europe – this was the perfect way to head into games they hope will lead to a home quarter-final.
Ruan Pienaar ended the night kicking five penalties and he converted the first-half tries of Jared Payne and Darren Cave to claim a 19-point haul.
Despite Ulster leading 20-0 just before half-time, Munster battled back with tries from Ivan Dineen, Dave Kilcoyne and James Coughlan to close at one stage to 23-19 in what was an absorbing contest.
But Ulster held their nerve and Pienaar kicked his final penalty in the last minute as Paul O'Connell was sin-binned, allowing the home side to recover from their defeat to Leinster last time out.
Pienaar, taking over the kicking duties from Paddy Jackson, got Ulster under way after three minutes with a penalty.
Ulster put the ball in the corner from the penalty and from the line-out Jackson's chip resulted in Jared Payne scoring to the right of the posts.
Pienaar then landed a monster penalty from just inside his own half to take Ulster to 13-0.
Keatley missed a second penalty after 20 minutes which led to a period of Ulster domination.
Ulster then scored a sensational try off a Munster turnover with Payne burning Paul O'Connell and setting Trimble free before Cave came in at an angle to score.
Pienaar's marvellous conversion made it 20-0 to Ulster, but the visitors immediately hit back and in the last play of the first half, Dineen touched down. Keatley again missed as he attempted to convert, with the ball bouncing off the post to narrow Ulster's lead to 20-5 at the turnaround.
In the second half, prop Kilcoyne was driven over from a line-out maul, with Keatley managing to kick his first points after four misses.
Pienaar made no mistake with a straightforward chance on the hour mark, a vital score to settle Ulster after conceding 12 points without reply.
But Munster again struck back and another driving maul from a line-out take from Peter O'Mahony saw the red shirts rumble over, with Coughlan getting the 65th-minute touchdown.
Keatley again converted and Munster were just four points behind, but with 10 minutes remaining Pienaar slotted his fourth penalty to again nudge Ulster further in front.
In the final minute, O'Connell was sin-binned by Alain Rolland for back-chat and Pienaar did the necessary.