Neath-Swansea 34 Munster 17: Two late Christian Cullen tries were not enough to prevent Munster succumbing to an opening Celtic League defeat as the Ospreys launched their season with a victory at St Helen's.
The Neath-Swansea combination held off a second-half fight back and clinched a bonus point with an injury-time touchdown from lock Lyndon Bateman.
The Ospreys' other tries came from scrum-half Jason Spice, centre David Bishop and replacement Adrian Durston.
Cullen inspired a Munster resurgence with two tries in the final quarter but they were always struggling to make up a 20-0 interval deficit.
The Ospreys were rampant before the break against opponents who were a pale imitation of the side who reached the Heineken Cup semi-finals last season.
All the rugby was played in the visitors' half as the fired-up Welsh sensed vulnerability in the Munster ranks but the first try did not arrive until the 36th minute when Spice powered across after good work in midfield from Elvis Seveali.
As Munster struggled to get in the game, Stefan Terblanche gathered a wild Munster pass to send Bishop sauntering over with Gavin Hanson on form with a boot, the Ospreys were in complete control at the break.
But with Jim Williams sparking an improved forward showing the visitors battled back with Cullen's scores. The result was never in doubt, however, as Durston and Bateman went over late on.