The Wales star kicked 20 points to give the Ospreys hard-earned revenge for defeat in the reverse fixture at Stradey Park last month.

The Ospreys deserved their 19-10 interval lead with Henson having supplied 14 of their points from his cultured right boot.

The Wales star got them off to a confident start with a sweetly struck drop-goal after only 62 seconds and then proceeded to give the Ospreys useful territory with a couple of siege-gun kicks to touch.

Henson and Mike Hercus swapped penalties in the space of two minutes before the Scarlets breezed into a 10-6 lead.

Matthew Watkins intercepted a telegraphed pass from outside-half Matthew Jones and raced in 60 metres for the converted try.

The second quarter was almost all Ospreys as the Scarlets’ set-piece scrum and line-out started to fail.

The on-song Henson bisected the posts with two more penalties, one from near halfway, while Barry Davies and Hercus were wide of the mark.

And in between the Scarlets’ penalty attempts the Ospreys were awarded a penalty try when the visitors’ scrum was demolished from five metres out.

The Scarlets went close to cutting the Ospreys’ lead when Alix Popham went in at the corner only to have a foot in touch.

And as the Scarlets made five replacements – including the whole front row - in the space of eight minutes, Henson missed his first penalty shot at goal.

It was the Scarlets who got on the scoreboard first after the break with a Hercus penalty, but that was cancelled out by Henson, who had been late-tackled, an offence which got Adam Jones sin-binned.

Five minutes later Jonathan Thomas followed Jones into the cooler following a professional foul.

Henson missed a long-range effort at goal but made up for it 10 minutes later with his fifth successful penalty as the Ospreys opened up a 12-point lead which they were to defend until the end.