Ulster suffered their first defeat of this season's Pro12 League with a 24-10 loss to Munster at Thomond Park.
Mark Anscombe fielded an inexperienced Ulster team which had Paul Marshall sin-binned in the first half.
Ulster trailed 10-3 at the break with Munster's dominance up front earning them a penalty try after 33 minutes.
Simon Zebo and Peter O'Mahony added tries for Munster but Ulster's Ali Birch scored his first try as the leaders stayed nine points clear.
Ulster won all 11 previous league outings this season but always faced an uphill task against an experienced Munster side as well as very difficult playing conditions at a rain-soaked Thomond Park.
Munster had the upper hand in the scrum and won a penalty try in the 33rd minute.
Ian Keatley converted, to add to a third minute penalty, to put the home side 10-3 ahead.
Immediately from the restart, Ulster scrum-half Paul Marshall was sin-binned for stamping on Donnacha O'Callaghan on what was a forgettable night for the half-back pairing of Marshall and Niall O'Connor.
Munster scored a try in the 45th minute, just before Marshall returned to the field, when Zebo spotted a huge gap in the Ulster midfield and ran in under the posts.
Flanker O'Mahony added a third try for Munster after 50 minutes as the home side cranked up the pressure in search of a bonus-point victory.
However, Ulster's defence held firm to deny their provincial rivals the all-important fourth try.
Ulster's management decided to empty their bench and there were impressive cameo performances from Michael Heaney and Birch who combined for a stoppage-time try.
Heaney's flip-pass back inside to Robbie Diack gave Birch the opportunity to score his first try for Ulster.
Rookie out-half Stuart Olding added a difficult conversion.
The win moved Munster up to third in the table but they will be disappointed not to have secured a five-point haul.
Ulster remain nine points clear of second-placed Scarlets, who visit Ravenhill in a top-of-the-table clash on Friday night.
Munster: Hurley, Howlett, Laulala, Downey, Zebo, Keatley, Murray, du Preez, Varley, Botha, Donnacha O'Callaghan, Holland, O'Mahony, O'Donnell, Butler.
Replacements: Sherry, Horan, Archer, Dave O'Callaghan, Coughlan,Stringer, O'Gara, Jones.
Ulster: D'Arcy, Cochrane, Allen, L Marshall, Gilroy, O'Connor, P Marshall, Black, Herring, Macklin, Stevenson, McComb, Diack, McComish, Wilson.
Replacements: Annett, Lutton, Court, O'connor, Birch, Heaney, Olding, Andrew.
Sin bin: P Marshall (35)
Referee: Alain Rolland (IRFU).