It was hardly convincing stuff from the West Glamorgan side, but the scrappy performance was enough for a second victory from three games to slightly ease the pain of the 37-10 capitulation in Cork.
The key to the victory was the Ospreys’ scrum, spearheaded by Wales props Duncan and Adam Jones. It created the opening try for Aled Brew and a penalty try before half-time.
The boot of fly-half Craig Warlow had kept the plucky Dragons in touch throughout, but they just lacked the cutting edge at crucial moments.
Warlow had given the Dragons an early 3-0 lead, but the writing was on the wall when the Ospreys shoved the visitors off their first scrum.
Flanker Steve Tandy pounced on the loose ball and skipper Leigh Davies floated a pass out to Brew who had a clear path to the corner.
The Dragons had flanker Jamie Ringer sent to the sin-bin for killing the ball at a ruck but the loss did not seem to do them much harm as Warlow reduced the arrears with his second penalty success.
However, as the Ospreys took control of the game the Dragons continued to fall foul of referee Nigel Whitehouse, with Kevin Morgan also seeing yellow.
There were some nervous final moments for home fans after Warlow made it 15-9 midway through the hald, and a breakaway by Luscombe five minutes into injury time almost snatched the game for the visitors.
But they had to be content with a losing bonus point for their efforts.
: Tries: Brew, Penalty. Cons: M. Jones. Pens: M. Jones.
: Terblanche, Mustoe, Parker, Davies, Brew, M. Jones, Spice, D. Jones, Bennett, A. Jones, Cockbain, Evans, Thomas, Tandy, Lloyd. Replacements: James for A. Jones (70), Newman for Cockbain (49), Wyn Jones for Lloyd (78).
: Pens: Warlow 3.
: Morgan, Wyatt, Luscombe, Bryant, Breeze, Warlow, Baber, Black, Crawford, R. Thomas, Gough, Charteris, Ringer, Forster, Bryan.
: Tuipulotu for Breeze (72), Robinson for Crawford (56). Ref: Nigel Whitehouse (Wales).