Munster (3) 16
- Tries: O'Mahony
- Cons: Hanrahan
- Pens: Hanrahan 3
Scarlets (3) 10
- Tries: Barclay
- Cons: A Thomas
- Pens: A Thomas
Ronan O'Mahony's try in the third minute of injury-time earned leaders Munster a last-gasp victory over unlucky Scarlets in the Pro12 clash.
The Scarlets felt Munster's Dave Kilcoyne had knocked on in the ruck before JJ Hanrahan's crosskick allowed O'Mahony to touch down.
An Aled Thomas break had set up John Barclay's try which put the Scarlets 10-3 ahead early in the second half.
But two Hanrahan's kicks cut the margin to a point before the late drama.
Munster's win at Musgrave Park increases their lead at the top to six points over Ulster.
As the match entered injury-time, it appeared as though Munster had blown their chance to record a ninth win in 10 Pro12 matches this season.
However despite misfiring for most of the contest, Munster were able to produce a big final effort and replacement scrum-half Duncan Williams's sniping run then brought them to within a couple of yards of the Scarlets line.
Munster fly-half JJ Hanrahan tries to get past Adam Warren
TV replays hinted that prop Kilcoyne had knocked on at the base of the ruck before Williams released the ball to Hanrahan in advance of the fly-half's crosskick.
Referee Nigel Owens also asked TV match official Dermot Moloney to check on whether O'Mahony was offside but the TMO was unable to rule on this because of the camera angle and decided that there was no conclusive proof of a Kilcoyne knock on.
With the decision ensuring Munster's victory, man of the match Hanrahan slotted the conversion from the touchline.
Munster began the game with only Casey Laulala, Cathal Sheridan and BJ Botha retaining starting places from
last weekend's dramatic Heineken Cup win in Perpignan.
Rain and wind in Cork meant that the first half wasn't a great spectacle with the only scores a Thomas 14th-minute penalty and Hanrahan's 23rd-minute reply.
Before the break, a turnover did allowed Scarlets centre Gareth Maule to produce a burst but Hanrahan averted the danger but forcing him into touch.
The action did liven up immediately after the restart as fly-half Thomas ghosted past Hanrahan and replacement Niall Scannell before releasing Barclay to score under the posts.
With Thomas adding the conversion, the Scarlets led by seven and for most of the second half, it looked as though the score would be enough to earn the visitors victory.
Hanrahan penalties in the 47th and 57th minutes did cut the margin to a point but apart from the Munster fly-half's long-range miss on 69 minutes, the home side rarely threatened until their late salvo.
Even being down to 13 players for the final four minutes after the sin-binnings of Rob Evans and Mike Poole appeared unlikely to deny the Welsh side.
Prop Evans was yellow carded in the 73rd minute for a line-out infringement with replacement Poole departing for a tip tackle on Barry O'Mahony.
But the gaps in the Scarlets defence allowed Williams to produce his burst in the second minute of injury-time and the drama that followed.
Denis Hurley; Gerhard van den Heever, Casey Laulala, Ivan Dineen, Andrew Conway; JJ Hanrahan, Cathal Sheridan; Dave Kilcoyne, Duncan Casey, BJ Botha, Ian Nagle, Billy Holland (capt), Dave O'Callaghan, Tommy O'Donnell, CJ Stander.
Niall Scannell for Casey 31, John Ryan for Botha 34, Donncha O'Callaghan for Dave O'Callaghan 48, Barry O'Mahony for O'Donnell 70, Duncan William for Sheridan 59, Ronan O'Mahony for van der Heever 58.
Not used: Alan Cotter, Johnny Holland.
Gareth Owen; Liam Williams, Gareth Maule, Adam Warren, Kristian Phillips; Aled Thomas, Rhodri Williams; Rob Evans, Ken Owens, Jacobie Adriaanse, Jake Ball, Richard Kelly, Josh Turnbull, John Barclay, Rob McCusker (capt), John Barclay.
Emyr Phillips for Owens 53, Shaun Hopkins for Barclay 75, Rhodri Jones for Adriaanse 53, Johan Snyman for Ball 56, Gareth Davies for R Williams 70, Rhys Priestland for Warren 62, Mike Poole for Owen 73.
Not used: D Thomas.
Nigel Owens (WRU)
David Wilkinson, Michael Black (IRFU)
John West (IRFU)