Leinster captain Sexton kicked two conversions in the opening period and three second-half penalties, the first of which took the Ireland and Lions fly-half past Felipe Contepomi as his province's all-time leading points scorer.

Leinster had enjoyed a 14-7 half-time lead thanks to the two tries from centre Rory O'Loughlin which Sexton had converted, either side of Ian Keatley's breakaway try, which the Munster out-half converted himself.

Crucially, Leinster were also staying on the right side of Welsh referee Ben Whitehouse, who sin-binned Munster hooker Niall Scannell after 20 minutes for a deliberate offside as the home side comfortably won the penalty count.

That continued into the second half as Sexton slotted three penalties after further indiscipline from the visitors, Keith Earls's two unconverted tries securing a losing bonus point and a flattering scoreline for Erasmus.

“It's not nice to come here and lose,” the Munster director of rugby said. “To get a losing bonus is a consolation but the penalty count was crazy, 8-1 at half-time and we only have ourselves to blame. But it was remarkable discipline shown by Leinster to only concede one penalty in the first 60 minutes.”

Munster captain Peter O'Mahony admitted poor discipline from his team was a concern ahead of an opening Champions Cup pool game at French side Castres next Sunday.

"It's always difficult regardless and when you go and concede eight-nine penalties in the first half you're going to put yourself under huge pressure,” O'Mahony said. “I don't know what the final tally was, but it was in the teens.

"As you can see we're trying hard, we're trying as hard as we can, but you have to give yourself a chance and we didn't today.

"We found ourselves in our own territory trying to exit, we certainly spent a lot of the game in our own half, we had very little time in their 22 certainly. You have to give yourself an opportunity and we didn't today, unfortunately.”

Yet O'Mahony took exception to a line of questioning from TG4 interviewer and former Leinster and Ireland prop Reggie Corrigan that suggested Munster were lacking in intensity. Asked about his post-match interview, the Reds captain said: “I think it's a silly question, essentially calling myself and my team-mates out and questioning do we want it enough.

"Myself I'm a very proud Munster man and Irishman and that's at the core of everything - everything is based around work-rate and you want to win, and for someone to question that I'd take huge offence at.”

While Munster have plenty to put right before their trip to France, Leinster must now prepare to face Top14 pacesetters Montpellier at the RDS next Saturday and head coach Leo Cullen acknowledged his side must take a “huge step up” for the visit to Dublin of an all-star team

“There are parts of our game that need to be better, I thought we were better than the last day and created a lot of opportunities out there,” Cullen said. “We probably need to be more ruthless, but it's more the defence that we have to look at because we gave away three tries.

“We'll turn our attention quite quickly to Montpellier because it will be a huge step up next week. But I thought it was up there, a really, really physical game and was played in the right spirit.”

LEINSTER: J Carbery; A Byrne, R O'Loughlin, R Henshaw, B Daly (F McFadden, 72); J Sexton – captain (R Byrne, 76), L McGrath (J Gibson-Park, 61); J McGrath (C Healy, 48), J Tracy (S Cronin, 48), T Furlong (M Bent, 48); D Toner, S Fardy (R Molony, 69); R Ruddock (J Murphy, 61), J van der Flier (R Ruddock, 72 - blood), J Conan.

MUNSTER: JJ Hanrahan; A Conway, C Farrell, T Bleyendaal (R Scannell, 66), K Earls; I Keatley (A Wootton, 44), C Murray (D Williams, 72); D Kilcoyne (L O’Connor, 67), N Scannell (R Marshall, 67), J Ryan (S Archer, 44); R Copeland (M Flanagan, 69), B Holland; P O’Mahony - captain, T O’Donnell (R Marshall, 29-31; J O'Donoghue, 63), CJ Stander.

Referee: Ben Whitehouse (Wales)