Unwanted Wales fullback Gavin Henson produced a superb performance in the Neath-Swansea Ospreys’ heart-stopping 33-26 victory over the Irish heavyweights at the St Helen’s ground in Swansea.

The brilliant 21-year-old was solid on defence, powerful in attack and slotted seven goals as he took advantage of a Munster side missing 13 first-choice players because of World Cup duty.

Ahead 23-12 at halftime, the Ospreys were in control for much of the match, scoring tries at regular intervals to keep the visitors at bay.

A late try to Munster fullback Jeremy Staunton – his second of the match – narrowed the margin to seven points, and the 5,000-strong crowd had to survive eight minutes of injury time as the Irish side pressed for the equalising try.

Munster opened the scoring when the home side fell for a Staunton dummy and the visiting fullback jogged in under the posts. It was Munster’s first try of the Celtic League tournament after 184 barren minutes of rugby.

It didn’t take long for the Ospreys to hit back. Fly-half Shaun Connor produced a pinpoint kick to the corner and winger Dave Tiueti climbed above opposite number Mossie Lawlor to palm the ball down to centre James Storey for the try.

Minutes later, Tiueti ran over the top of Lawlor to score in the right-hand corner, and Henson’s sideline conversion gave the Ospreys a deserved 17-7 lead.

Henson added another penalty goal, but Munster came back into the match when unwanted Ireland flanker David Wallace took advantage of a three-man overlap to score.

Home scrum-half Andy Williams brought the crowd to their feet early in the second half when he stole the ball out of the back of the Munster scrum and scampered 25 metres unopposed for the Ospreys’ third try. Henson’s conversion gave his side an 18-point lead and Munster a mountain to climb to get back into contention.

But they tried. Veteran centre Mike Mullins came back on the angle from close range to power over and Staunton’s conversion narrowed the gap to 11 points on the hour mark.

The Ospreys fans were made to sweat when Mullins and Staunton produced a piece of midfield magic for Staunton’s second five-pointer, but Henson’s huge punts kept his side out of trouble as the clock ran down.