Munster reclaimed top spot in the Pro12 with a gutsy win over lively Ospreys at Liberty Stadium.
The visitors were 13-8 ahead at the break through Sean Dougall's early try and Ian Keatley's conversion and two penalties.
Ospreys' response came from Sam Davies' penalty and Ashley Beck's well-taken try.
But Simon Zebo's long-range effort and James Downey's strong finish proved decisive.
The hosts remained third despite defeat after fourth-placed Glasgow were beaten 24-23 by Newport Gwent Dragons.
But for Munster victory meant overtaking Irish rivals Leinster in the pecking order after they edged the forward battle and out-witted the hosts' attacking strategy.
Ospreys were also guilty of fluffing their chances at crucial moments, particularly in a second period in which they were often on the front foot..
With Wales and Ireland having stripped away many top stars from this top-four encounter amid the Six Nations, there were opportunities for others to shine.
In the absence of Wales squad flanker Justin Tipuric, Sam Lewis took the man-of-the-match award.
But his efforts were in vain.
Flanker Dougall claimed the opening try after a driving line-out and fly-half Ian Keatley converted from wide out.
Munster's scrum won a penalty that allowed Keatley to extend his side's lead after 16 minutes.
And Keatley responded from 40 metres after home full-back Davies' penalty to maintain their 10-point lead.
Davies hit an upright with a long-range penalty before centre Beck shrugged Keatley's high challenge before his pace and neat footwork took him to the line.
Davies missed the conversion and a long-range penalty who the final kick of the first half.
After the break the hosts again took the game to Munster, but the attack broke down and Zebo gathered before twisting out of a tackle and running 60 metres to score.
Home hooker Scott Baldwin was also thwarted as he illegally crawled to the line, his effort ruled out by television match official Tim Hayes, who also called a penalty.
Davies rewarded the Ospreys with a 68th-minute penalty, but replacement Munster fly-half JJ Hanrahan's eye for the gap and well-timed pass sent Downey on his way to the line.
Hanrahan converted and the hosts finished with 14 men after replacement Ryan Jones was sin-binned in the dying moments.
Ospreys: Sam Davies; Aisea Natoga, Jonathan Spratt (capt), Ashley Beck, Jeff Hassler; Matthew Morgan, Tom Habberfield; Duncan Jones, Scott Baldwin, Dan Suter, Perry Parker, James King, Tyler Ardron, Joe Bearman, Sam Lewis.
Replacements: Matthew Dwyer, Marc Thomas, Joe Rees, Ryan Jones, Dan Baker, Tito Tebaldi, Hanno Dirksen, Richard Fussell.
Munster: Felix Jones; Andrew Conway, Casey Laulala, James Downey, Simon Zebo; Ian Keatley, Cathal Sheridan; James Cronin, Duncan Casey, BJ Botha, Donnacha Ryan, Dave Foley, Tommy O'Donnell, James Coughlan (capt), Sean Dougall.
Replacements: Ger Slattery, Dave Kilcoyne, Stephen Archer, Donncha O'Callaghan, CJ Stander, Duncan Williams, JJ Hanrahan, Denis Hurley.
Referee: David Wilkinson (IRFU)
Assistant Referees: Wayne Davies, Jon Mason (both WRU)
Citing Commissioner: Jeff Marks (WRU)
TMO: Tim Hayes (WRU)