Two tries from Leinster scrum half Tania Rosser saw champions Munster downed 12-5 in the second round of the IWRFU Interprovincial Championship on Saturday.
IWRFU INTERPROVINCIAL CHAMPIONSHIP: SECOND ROUND: Saturday, October 22
Munster 5 Leinster 12, Musgrave Park
Ulster 14 Connacht 0, Malone RFC
THIRD ROUND FIXTURES: Saturday, November 19/Sunday, November 20
Ulster v Leinster, tbc
Connacht v Munster, tbc
Rosser, a 27-year-old teacher who plays for Blackrock, was the shining light for Leinster as they handed their bitter rivals from the south their first defeat in four seasons.
The Ireland international touched down in either half in a poor game that saw the high stakes get to some of the players. The fact that this was the first time Munster's women's team had played an Interpro fixture at Musgrave Park only lent to the tension.
Leinster's pack was on song in the early stages and a break by returning number 8 Orla Brennan put the supporting Rosser in for her first try after only five minutes. Rosser showed an excellent turn of pace to score.
Leinster missed the conversion and gradually Munster came back into the proceedings despite a malfunctioning lineout. Tony Trehy's side got it back to 5-5 by half-time as vice-captain Jean Lonergan of Shannon got in at the left corner after an initial incision by her club mate Joy Neville.
Munster turned down a close-in penalty chance early in the second half with Ireland captain Sarah-Jane Belton being asked to kick for the corner, and that decision came back to haunt the hosts in the closing stages.
Munster muddled up when attempting to run the ball out from their own 22. Belton tried to release her backs, one poor pass was gobbled up by Rosser and she linked again with Brennan. With only Carol Murphy to beat, the Leinster number 9 then brilliantly stepped inside the Munster left winger to race over and score.
Rosser was repeating her trick of last season's meeting when she also scored two tries in a thrilling 20-20 draw at Clontarf RFC. Navan winger Jackie Shiels crowned Leinster's win at Musgrave with an excellent conversion from far out.
At Malone RFC on Saturday, Ulster picked up their first points of the campaign - winning 14-0 against Connacht - to keep themselves in the hunt for a place in next month's play-off final.
Armagh teenager Christine Robb, who was included in the Ireland squad last season, came off the bench to score a try in each half with returning lock Rachel Reid converting both efforts.
Connacht were unfortunate not to go in front when Angela Flaherty dinked a penalty off an upright, but Ulster were altogether too powerful for the visitors.
Ulster captain Suzanne Fleming sent Robb racing through for her first shortly before the break and on 68 minutes, full-back Joy Sparkes carved out the opening for Robb's second.