John Kelly's try 40 seconds into injury-time saw Munster earn their seventh bonus point of the Celtic League campaign and complete the double over Leinster with a 24-13 at Musgrave Park.
The visitors held onto a three-point half-time advantage for three quarters of the second half but Rob Henderson's try after 71 minutes and Kelly's second of the game, arrowing through a slack Leinster rearguard, saw the men in red earn their fourth straight win.
On a crisp Cork night Leinster, a place below the hosts in the table, were kicked into the lead by Matt Leek's third-minute penalty. Munster's Mossie Lawlor replied three minutes later when he ended a sweeping move which saw flanker Eddie Halvey loop a pass out wide for the left winger to romp home.
Out-half Jason Holland missed with the conversion, his first miss of four in total. Leinster regained the lead after 15 minutes despite seeing prop Peter Coyle sin-binned, with Leek's second penalty this time from the left. Henderson inspired Munster and Kelly's first try as his booming kick paved the way for a swift line-out move and switch with Holland before the centre put Kelly over to the left of the Leinster posts.
However with Munster second row David Pusey sin-binned for infringement, Leinster regained the lead in the third minute of stoppage time, as Aidan Kearney bumped off a tackle from Jason Jones-Hughes to ground the ball after a Leinster maul.
An incisive Henderson break saw South African Shaun Payne advance from his full-back position only to trip over with the Leinster line in sight after five second-half minutes. But it was the number 15's midfield break which saw Henderson touch down after six pairs of Munster hands had handled the ball from their own 22 to the visitors' line with nine minutes remaining.
Kelly's effort confirmed another late bonus point win for Munster, following last Friday's injury-time show against Borders.
Ulster stayed top of the table with a four-try 31-19 win over Neath-Swansea Ospreys in a one-sided match as the spirited visitors struggled to stay in touch throughout.
Even with speculation continuing over coach Alan Solomons' future at Ravenhill, Ulster stuck to their task and scored three tries in a 13-minute period of the first half.
Ospreys battled back to 24-12 after an hour, before Ulster finally grabbed their bonus point with a score from replacement Warren Brosnihan. Ulster outside-half Adam Larkin ended the night kicking four conversions and a penalty, as the home side registered their ninth win of the campaign.
The table-toppers opened the scoring after six minutes with a Larkin penalty. They should have stretched their early lead three minutes later, but Larkin's second penalty attempt rebounded off an upright. Ulster made amends after 12 minutes when a Paddy Wallace half break put Neil Best clear for the touchdown. Larkin added the points and did so again three minutes later when a Wallace break put Scott Young clear to dot down.
Five minutes before the half-hour Ulster grabbed a third score when Wallace made the left corner after great initial work by captain Andy Ward. Larkin added a great conversion, and Ulster seemed out of sight at 24-0. But Ospreys hit back after Ulster had a fourth try, by Larkin, disallowed following an apparent punch thrown by Best.
Gareth Morris burst through against the run of play, and Gavin Henson added the two points to make it 24-7 at the break. After a scrappy start to the second half, an Ospreys line-out near the Ulster line on the hour saw captain Williams cross after the visitors drove over the line.
Gavin Henson missed the conversion, but Ospreys had closed it to 24-12. Ulster grabbed their bonus point eight minutes after the hour when Brosnihan was driven over from a line-out. Larkin converted, and Ulster were back in the driving seat at 31-12. All that remained was for Dave Tiueti to grab a consolation injury-time score which Shaun Connor converted.