A late try by debutante Brian Carney gave Munster a rare victory at Ulster's Ravenhill in the Magners League on Friday.
Carney struck with five minutes to go of a rugged Irish derby as Munster bounced back from being 21-3 down at the break to win 21-24.
The visitors simply torched the script - which had Ulster racking up a few tries - and came back to snatch the win which appears to have done fatal damage to Ulster's Magners League challenge.
Ulster's intent had been to top the table outright overnight, ahead of Leinster's game with Connacht on Saturday, but their losing bonus point puts them on equal points with Michael Cheika's side and is bound to leave Ulster deeply wounded after losing control of a game they had initially dominated.
Instead of pushing on to secure the bonus point, Ulster's game and defensive shape fell apart as the going got fast and loose in the second half.
Ulster ignored a kickable penalty attempt, which could have drawn the game in the dying minutes, to go for a try but Munster's excellent defence held firm.
The momentum never returned to the home side's game and Ulster failed to score any points from the 24th minute onwards.
Tommy Bowe came close to scoring in the seventh minute and only a great covering tackle from Christian Cullen prevented the home side from getting out of the traps early.
But Ulster were not to be denied and a minute after Cullen's heroics, Andrew Trimble found Paul Steinmetz on a cutback run off the left wing and the Kiwi burst through to score under the posts and give David Humphreys a straightforward two-pointer.
The visitors' cause was further damaged by the sinbinning of prop Tony Buckley after a fracas with Justin Harrison from the restart and Ulster used the 10 minutes well by producing a score from Roger Wilson, again converted off the upright by Humphreys, to give them a 14-0 lead after 20 minutes.
With Munster restored to their full complement, Eoghan Hickey managed their first points from a penalty but the home side immediately struck back when, from a scrum, Humphreys put Trimble clear though referee Allain Rolland failed to notice a blatant forward pass from Ulster's outside half.
With Humphreys adding his third conversion Ulster now led 21-3 and looked odds on to secure a bonus point.
Seven minutes before the break, they nearly got their score with Trimble only hauled down by a last ditch tackle from Ian Dowling and then Rory Best crossed the line but the try was disallowed due to obstruction and Ulster had to be content with their 21-3 lead at the break.
But that was as good as it got for Ulster. Five minutes after the restart, John O'Sullivan's gut-busting break from his own 22 set up a try for Trevor Halstead and with Hickey's conversion Munster - missing virtually their entire first-choice side - had closed Ulster's lead to 21-10.
Three minutes after the hour, the crucial score arrived after Paddy Wallace carried the ball over his line under pressure from the advancing red hordes.
O'Sullivan picked up from the five metre scrum and substitute outside half Jeremy Manning converted his score.
Munster were right back in it and only trailed by four points.
With Humphreys retiring hurt, Ulster never regained their shape, though in truth their forward effort had already imploded.
Five minutes from time, after some fantastic ball retention, Carney scored off Alan Quinlan's cross kick and Manning converted.
Tries: Steinmetz, Wilson, Trimble
Cons: Humphreys 3
Tries: Halstead, O'Sullivan, Carney
Cons: Hickey, Manning 2
Yellow cards: Buckley (Munster, 12)
Ulster: 15 Bryn Cunningham, 14 Tommy Bowe, 13 Paul Steinmetz/Andrew Trimble, 12 Paddy Wallace/Paul Steinmetz, 11 Paul McKenzie/Andrew Trimble, 10 David Humphreys/Paddy Wallace, 9 Isaac Boss, 8 Roger Wilson, 7 Kieron Dawson, 6 Stephen Ferris, 5 Ryan Caldwell, 4 Justin Harrison (c), 3 Bryan Young, 2 Rory Best, 1 Justin Fitzpatrick,
Replacements: 16 Paul Shields, 17 Simon Best/Declan Fitzpatrick, 18 Tim Barker, 19 David Pollock, 20 Kieran Campbell, 21 Paul McKenzie/AN Other, 22 Andrew Maxwell.
Munster: 15 Christian Cullen, 14 Barry Murphy, 13 Lifeimi Mafi, 12 Trevor Halstead, 11 Ian Dowling, 10 Eoghan Hickey, 9 Tomas O'Leary, 8 John O'Sullivan, 7 Tim McGann, 6 Alan Quinlan, 5 Chris Wyatt, 4 Donnacha Ryan, 3 Tony Buckley, 2 Jerry Flannery, 1 Eugene McGovern,
Replacements: 16 Tim Ryan, 17 Frankie Sheahan, 18 Mark Melbourne, 19 AN Other, 20 Brian O'Meara, 21 Jeremy Manning, 22 Brian Carney or Keith Earls.
Referee: Alain Rolland (Ireland)
Touch Judges: David Keane (Ireland), John Carvill (Ireland)
Assessor: Jim Irvine (Ireland)