Both sides needed to win for different reasons as the third-placed Ospreys lay just one point off Glasgow Warriors above them and seven behind runaway leaders Munster.

The Dragons are at the opposite end of the table and the win took them above arch rivals Cardiff Blues, a side they play on Boxing Day at Rodney Parade.

Within the opening quarter of an hour of the match the lead changed hands three times.

Outside-half Dan Biggar put the Ospreys ahead with a penalty before pressure on their line saw big flanker Hoani MacDonald take a line-out, hooker Steve Jones go through a gap and scrum-half Robert Lewis dive in at the corner.

Biggar's second penalty put it back to 6-5 for his team but yet again the Dragons had their opponents on the goal-line for Wales prop Rhys Thomas to dive over.

There were suspicions he had dropped the ball but, after a view from fourth official Gareth Simmonds on the replay, the try was given and converted by outside-half Shaun Connor.

Connor booted another penalty to extend the home side’s lead before the Ospreys managed to get into the game eight minutes before the break.

Wales RBS 6 Nations ace Gavin Henson, playing his first match in six weeks for his region due to injury and the birth of his second child, finished off a well-worked move across the backs to go over in the corner.

A third Biggar penalty from 42 metres cut the difference to just a single point at the break in the Dragons’ favour.

Within 30 seconds of the restart the Dragons regained their four-point advantage when Connor put over a penalty.

A rousing cheer was reserved for Ospreys scrum-half Mike Phillips, who came on as a replacement on 50 minutes for his first run-out after nine months of injury.

The sides then exchanged tries within a minute of each other, MacDonald giving Dragons wing Gareth Wyatt a scoring pass before centre Parker sent Henson in for his second.

As the rain sheeted down just after the hour, Biggar had a chance to regain the lead when the Dragons came offside at a ruck but pushed his 30-metre shot wide.

It was all the Ospreys as the game entered the final 10 minutes but a combination of excellent home defence and mistakes by the visitors kept the Dragons in front at 23-21.

But the Dragons got their try bonus point when flanker Colin Charvis kicked over the top of the defensive line for full-back Jason Tovey to latch onto and score.

Connor's conversion put the home team seven points ahead. That lead was cut by a fourth Biggar penalty but it was not enough to deny the home side the win.