Munster came from behind at half time to grind out a 16-6 win over Ulster at Ravenhill on Friday.
A makeshift Munster side stayed top of the Magners league after centre Ivan Dineen marked his debut with a last-minute try to snatch a losing bonus point away from the hosts.
Dineen latched onto an attempted Ian Humphreys flick pass to run in under the posts and seal Munster's first win in Belfast since 2007 after Paul Warwick's 69th-minute penalty had put the visitors 9-6 ahead.
Ulster who have now lost three games in succession and failed to score a single point in the second half with recent signing Ruan Pienaar missing a straightforward penalty to tie the scores with only seven minutes remaining.
After their recent troubles Ulster needed to start well and duly did so, with Ian Whitten offloading to fellow centre Nevin Spence.
Spence charged into space and put Ulster on the front foot deep in Munster's 22, ultimately leading to Pienaar's opening penalty after six minutes when the visitors strayed offside.
But Ulster failed to deal with the restart and when Johann Muller and Robbie Diack collided, Munster pounced on the ball and Paul Warwick levelled the scores after Ulster were penalised at a ruck.
Pienaar's second penalty put Ulster back in front but that was as good as it got for the home side.
Pienaar was wide with a long-range penalty attempt just after the half hour and then, in the final action of the half, Spence again made a strong break but Adam D'Arcy was unable to get on the ball as it rolled over the line from a chip.
The second half opened with Warwick's second penalty to tie the scores again after Ulster fumbled from the restart, and then only a frantic last-ditch turnover saved Ulster from conceding a try as the Munster pack began to turn the screw.
Ulster responded with a period of dominance from their own forwards but Munster held firm when put under pressure from Pedrie Wannenburg and replacement Chris Henry.
However, it was Wannenburg who gave away the penalty after 68 minutes, for not rolling away at a ruck, from which Warwick made it 9-6.
Pienaar should have made it 9-9 in the 77th minute
but his kick sailed wide and Munster then sealed the win when Humphreys' pass was snaffled by Dineen and he was in under the posts with the last play of the game.
Warwick duly added the extras to complete Ulster's misery on a night when Peter Stringer made his 200th appearance for Munster.
Pens: Pienaar 2
Pens: Warwick 3
Ulster: 15 Adam D'Arcy, 14 Mark McCrea, 13 Ian Whitten, 12 Nevin Spence, 11 David McIlwaine, 10 Ian Humphreys, 9 Ruan Pienaar, 8 Robbie Diack, 7 Willie Faloon, 6 Pedrie Wannenburg, 5 Tim Barker, 4 Johann Muller (capt), 3 Bryan Young, 2 Nigel Brady, 1 Paddy McAllister.
Replacements: 16 Andi Kyriacou, 17 Jerry Cronin, 18 Alan Whitten, 19 Dan Tuohy, 20 Chris Henry, 21 Paul Marshall, 22 Niall O'Connor, 23 Luke Marshall.
Munster: 15 Scott Deasy, 14 Doug Howlett, 13 Johne Murphy, 12 Ivan Dineen, 11 Denis Hurley, 10 Paul Warwick, 9 Peter Stringer, 8 James Coughlan, 7 Niall Ronan, 6 Alan Quinlan, 5 Ian Nagle, 4 Billy Holland, 3 John Hayes, 2 Mike Sherry, 1 Wian du Preez.
Replacements: 16 Sean Henry, 17 Darragh Hurley, 18 Stephen Archer, 19 Tommy O'Donnell, 20 Peter O'Mahony, 21 Duncan Williams, 22 Barry Murphy, 23 Simon Zebo.