A last ditch try from JJ Hanrahan saw Munster stun Perpignan 18-17 at the death in their pivotal Heineken Cup clash at Stade Aimé Giral on Saturday.
The memorable victory puts the Irish outfit six points clear of Pool rivals Gloucester, who tackle struggling Edinburgh at Kingsholm on Sunday.
Perpignan thought they had sealed the four points when Tommaso Benvenuti scored in the 77th minute but a moment of magic involving Tommy O'Donnell and fellow replacement Hanrahan broke Perpignan hearts in a heated encounter.
Munster now know that their fate is very much in their own hands ahead of facing Gloucester and finally Edinburgh in January's final two games.
Munster went into the game on the back of a convincing 36-8 victory over their French opponents last week, starting strongly, only to fall behind to a Tommy Allan penalty.
The game was then marred by yellow card's for both sides, with Romain Terrain and Peter O'Mahony sent to the bin for an off the ball scrap.
Ian Keatley and Allan then exchanged three pointers, in a scrappy half which lacked both excitement and quality.
The visitors' poor discipline didn't help them in an ill tempered first half, as they conceded another penalty, this time for offside, which put them six points behind.
Munster came out firing at the start of the second period, forcing the Perpignan scrum onto the back foot with some dominant scrum play. After four consecutive five metre scrums, referee JP Doyle finally decided to award the penalty try for the travelling team, who edged into a narrow lead.
Momentum then shifted once more, as Munster scrambled to keep out a resurgent home side. Allan's penalty was all they had to show for it though, with several chances spurned. They paid for their profligacy soon after.
Keatley tipped the game back in his side's favour once more, a penalty meaning they held on to a one point gap going into the final ten minutes.
Allan then missed the chance to change the scoreline once more, missing a kickable chance to keep Munster's noses in front.
Benvenuti then thought he had won the game, only for Munster to record an unbelievably dramatic win, as replacement Hanrahan charged over in the corner with 80 minutes up.
Pen: Allan 4
Tries: Penalty, Hanrahan
Pen: Keatley 2
Perpignan: 15 Joffrey Michel, 14 Richard Haughton, 13 Lifeimi Mafi, 12 Watisoni Votu, 11 Sofiane Guitoune, 10 Tommy Allan, 9 Nicolas Durand, 8 Luke Narraway (c), 7 Al Strokosch, 6 Daniel Leo, 5 Guillaume Vilaceca, 4 Sebastien Vahaamahina, 3 Paulica Ion, 2 Romain Terrain, 1 Sebastien Taofifénua.
Replacements: 16 Guihelm Guirado, 17 Pascal Cotet, 18 Jean-Baptiste Custoja, 19 Justin Purll, 20 Tom Ecochard, 21 David Marty, 22 Tommaso Benvenuti, 23 Jean-Pierre Perez.
Munster: 15 Felix Jones, 14 Keith Earls, 13 Casey Laulala, 12 James Downey, 11 Johne Murphy, 10 Ian Keatley, 9 Cathal Sheridan, 8 James Coughlan, 7 Sean Dougall, 6 Peter O'Mahony (c), 5 Paul O'Connell, 4 Donnacha Ryan, 3 BJ Botha, 2 Damien Varley, 1 James Cronin.
Replacements: 16 Duncan Casey, 17 Dave Kilcoyne, 18 Stephen Archer, 19 Donncha O'Callaghan, 20 Tommy O'Donnell, 21 Duncan Williams, 22 JJ Hanrahan, 23 Denis Hurley.
Referee: JP Doyle (England)
Assistant referees: Martin Fox, Paul Dix (both England)
TMO: Rowan Kitt (England)