Munster sit sixth in the league table after slipping to their second successive defeat at the hands of Welsh opposition.

Declan Kidney's side failed to make the most of their try-scoring opportunities and also had two touchdowns ruled out for knock-ons as their losing league record against the Ospreys in Wales continued.

Kidney included Ireland World Cup squad members Brian Carney and Alan Quinlan from the off and sprung their fellow internationals Peter Stringer and Frankie Sheahan from the bench in the second half, but the international-laden home side just held the edge.

As well as try scorer Williams, there were nine other members of the Welsh World Cup panel in the Ospreys matchday squad and they were determined to impress with Wales caretaker coach Nigel Davies an interested spectator.

The Ospreys, who also started Scottish international Nikki Walker, opened the scoring in the third-minute when their 18-year-old out-half Gareth Owen booted a penalty.

Munster competed well at the breakdown on the opening half and won three penalty kicks inside the first 22 minutes which, on a better day, Paul Warwick might have bisected the posts with.

Unfortunately for the visitors, Warwick's radar was off and he missed all three kicks, hitting one off the post, as Munster remained scoreless until 55 minutes into the tie.

They were also missing that crucial ingredient of luck as tighthead prop Tony Buckley missed out on a first half try. A kick through from Quinlan and a good chase from Carney, who scored a try in last season's corresponding fixture, led to Buckley crashing over but the effort was ruled out for an earlier knock-on.

Television match official Hugh Watkins also deemed that scrum half Mike Phillips, who was making his home debut for the Ospreys, had been held up over the try line by Munster's Ian Dowling.

But the defending champions had success with two more of Watkins' TMO decisions before half-time. Just after the half-hour mark, youngster Owen made a blindside break and fed full-back Lee Byrne who, despite being tackled by Kieran Lewis, used his momentum to slide over the whitewash.

Watkins confirmed the try which Owen failed to convert from a difficult angle. Just three minutes later, the hosts were celebrating their second try when man of the match Byrne turned creator and he spun a pass out for Williams to squeeze in at the corner.

13-0 in front at the break, Lyn Jones' side move further ahead when Owen right-footed a 48th-minute penalty through the posts.

Seven minutes later, Munster belatedly got off the mark as replacement out-half Jeremy Manning landed a penalty after Owen was yellow carded for killing the ball at a ruck.

That should have been the signal for Munster to pile on the pressure and points, but despite having the better of the closing half-hour and benefiting from the sparky contribution of Stringer, Kidney's charges could not add to their tally.

The scores dried up for both sides, whose error counts increased as a plethora of replacements got a run-out in what was a poor quality game given the players on show.

That left the Ospreys to see out their second win in three league games, although given the strength of their starting line-up - as opposed to Munster's - the victors' performance, on a whole, was disappointing.

For Munster, their October 26 trip to Glasgow should see the return of their full World Cup contingent and hopefully a return to winning ways.