A controversial yellow card against Glasgow’s Stuart Hogg late in the game allowed Munster to snatch victory and in all probability top place in Pool One of the European Champions Cup at Scotstoun.
The Scotland full-back made contact with the head Munster’s Andrew Conway close to the line and although the impact was minimal, under rugby’s new regulations referee Luke Pearce felt he had little choice but to sin-bin the Warrior.
Munster scored the game’s only try from replacement Francis Saili almost immediately and held out for the narrow win that means the Warriors now have to win against Leicester at Welford Road next week to reach the quarter-finals.
Glasgow enjoyed most of the ball especially in the second half but only had four penalties, three from Finn Russell and one from Hogg, to show for their efforts. Munster were barely an attacking threat and kicked most of their possession even off first phase.
Warriors’ Tim Swinson was a deserved man of the match and Russell was bright and inventive, but Munster’s collective will was formidable to see them through to win they barely deserved.
The first half was played the way the visitors would have wanted it; tight, physical, with the ball in the air as much as it was in the hands.
Glasgow’s best chance at a score came early when Russell chipped over the rushing Munster defensive line into the 22 and the bouncing ball just eluded his grasp, CJ Stander saving the day for the Irishmen with the recovery.
Russell booted a penalty after 13 minutes as Munster struggled at a scrum, but although Tyler Bleyendaal was short with an ambitious attempt from halfway in return, a high tackle by Lee Jones on Simon Zebo gave the Kiwi fly-half an easier chance to level the scores after 20 minutes.
Munster enjoyed their best spell for the next ten minutes and one last-gasp turnover prnalty on the deck saved Glasgow from a perilous situation, and another on halfway soon after gave Hogg the chance to show his long-range ability with the three points.
However the lead lasted just two minutes as Strauss was penalised at a ruck and Bleyendaal levelled the scores again, although Hogg was just wide with another long-range attempt just as the half ended.
Glasgow owned territory and possession for the first 29 minutes of the second half but still only held a fragile three-point lead at the end of it.
Russell almost sprung Tim Swinson through a gap but Munster regrouped at the expense of a penalty kicked by the Glasgow stand-off, but they gave the three points right back when penalised at a ruck.
Once again the home side then dominated the ball but couldn’t force a way through Munster’s swarming defence and had to make do with just another Russell penalty to lead 12-9 going into the final ten minutes.
However a poor kick from Price gave Munster their first real attacking platform of the half and they made it pay in controversial circumstances.
After several surges at the Glasgow line they moved it wide for wing Andrew Conway, who was clipped by a flying arm from Hogg before being held up over the line, but Pearce and the TMO adjudged the Scotland full-back’s contact merited a yellow card.
Munster kicked the penalty to the corner and worked space against the 14 men for replacement Francis Saili to score the game’s only try in the opposite corner, Bleyendaal’s conversion going wide.
Glasgow had one more chance to work position with a charge down from Swinson but a fumble in midfield allowed Munster to close out the game.
Glasgow: S Hogg; T Seymour, M Bennett, A Dunbar, L Jones; F Russell, A Price; G Reid, F Brown, Z Fagerson; T Swinson, J Gray (capt); R Harley, R Wilson, J Strauss.
Replacements: P MacArthur for Brown 63, A Allan for Reid 78, D Rae for Fagerson 78, C Fusaro for Strauss 68, N Grigg for Bennett 63.
Munster: S Zebo; A Conway, J Taute, R Scannell, K Earls; T Bleyendaal, C Murray; D Kilcoyne, N Scannell, J Ryan; J Kleyn, D Ryan; P O’Mahony (capt), J O’Donoghue, CJ Stander.
Replacements: R Marshall for N Scannell 67, J Cronin for Kilcoyne 48, T du Toit for Ryan 61, D Foley fo O’Mahony 73, B Holland for Kleyn 54, I Keatley for Zebo 73, D Saili for Taute 57.
Ref: L Pearce (RFU)