In south Wales on the other hand Johnny O'Connor's injury time try gave Connacht a victory that leaves them five points adrift of the Dragons whose games in hand include trips to Dublin and Swansea.
Leinster's defeat will serve to remind Munster of how things might have been only for that costly slip up at the Arms Park and their uncharacteristic lacklustre display at home to the champions elect back in November.
This evening there's the opportunity to avenge the earlier season 16-3 defeat by the Ospreys. Back in October, Lee Byrne and Shane Williams were the Ospreys try scorers and both are in the side side for tonight's game as are most of the Ospreys Grand Slam contingent with the exception of Mike Philllips whose replacement comes in the not inconsiderable shape of former All Black legend Justin Marshall.
Munster: Shaun Payne; Brian Carney, Barry Murphy, Kieran Lewis, Anthony Horgan; Paul Warwick; Tomas O'Leary; Federico Pucciariello, Frank Sheahan,Tony Buckley; Mick O'Driscoll, Paul O'Connell capt; Donnacha Ryan, Niall Ronan, Denis Leamy. Replacements: Marcus Horan, Jerry Flannery, Anthony Foley, David Wallace, Peter Stringer, Jeremy Manning, Keith Earls.
Ospreys: Lee Byrne; Johnny Vaughton, Sonny Parker, Andrew Bishop,Shane Williams; James Hook, Justin Marshall; Filo Tiatia (Capt), Marty Holah, Jonathan Thomas; Ian Evans, Ian Gough; Cai Griffiths, Huw Bennett, Duncan Jones.
Replacements: Ed Shervington, Andrew Millward, Lyndon Bateman, Ben Lewis, Gareth Owen, Jonathan Spratt, Aled Brew