Munster defeated a weakened Leinster 29-17 at Thomond Park to extend their lead at the top of the Guinness PRO12 to five points.

The IRFU's player welfare programme prevented Leinster from fielding the vast majority of their Ireland internationals, arguably deciding the result of this festive derby before kick-off, with Munster virtually at full strength.

Ronan O'Mahony's try just before half-time was added to by 15-point blitz -- including scores from Tommy O'Donnell and man-of-the-match CJ Stander -- that wrapped up the bonus point for Rassie Erasmus' men by by the hour mark.

Leinster scored first and last in Limerick but came away with nothing to show for their efforts, Zane Kirchner zooming over in the 17th minute and Richardt Strauss' consolation effort coming with just four minutes remaining.

Both sides hurtled into tackles early on in front of the capacity 26,200 crowd, Stander knocking on after a bout of early pressure from Munster, while Tyler Bleyendaal and Ross Byrne, Leinster's young fly-half, also probing effectively with the boot.

Leinster, who were thwarted by an earlier lost lineout, used scrum possession to unlock the home defence just past the quarter hour, full-back Kirchner taking a direct line to the whitewash after crisp passing from half-backs Jamison Gibson-Park and Byrne.

Munster were level within five minutes, though, building from a lineout in the 22 before Simon Zebo showed brilliant awareness to twist out of attempted tackles from Gibson-Park and Barry Daly and dot down just inches away from the right corner flag. Bleyendaal's conversion attempt went over with the aid of the crossbar.

Leinster captain Isa Nacewa punished a neck-roll by Jean Kleyn to kick the visitors back in front at 10-7, the tit-for-tat exchanges continuing up front as Dan Leavy won a breakdown decision and Jaco Taute's well-timed tackle led to a monster counter ruck from the Munster forwards.

The hosts had nothing to show for a prolonged attacking spell which included a clever Conor Murray chip and a between-the-legs pass from James Cronin.

However, their efforts were rewarded past the 40-minute mark, a frenzied 21 phases leading to Bleyendaal sending winger O'Mahony over in the right corner, with Bleyendaal's excellent touchline conversion giving them a 14-10 interval advantage.

Kirchner avoided sanction for a tackle off the ball on Darren Sweetnam just before the try, the latter's replacement Andrew Conway soaring to claim a high ball and keep Munster on the front foot early in the second period.

The third quarter was where Munster really put the game to bed, aided by some marginal calls by referee Nigel Owens and his Irish match officials.

On another night, James Tracy would have been rewarded for his work at the breakdown five metres from his own line, but Munster managed to retain possession and Conor Murray's cross-field kick was juggled and then dotted down, wide on the right, by flanker O'Donnell.

That seven-pointer was followed by five more from Stander, the powerful number eight driving over from a lineout maul on the opposite wing in the 56th minute.

With the bonus point in the bag, Bleyendaal booted a 61st-minute penalty to put Munster out of sight at 29-10 -- but only after their loosehead Cronin was allowed to come in on an angle at a scrum the hosts won against the head.

As the men in red, including a fit-again centre Francis Saili, continued to flood forward, it took some excellent tackling and rucking from Jack Conan to prevent a certain try.

And it was the visitors who had the final say as a late surge saw replacement hooker Strauss spring free from a maul to the right of the posts.