The Ospreys stayed in contention for a PRO12 play-off berth after beating the Dragons 14-3 at Rodney Parade on Monday.
Eli Walker's converted try gave the away team an early lead before Tom Prydie hit back for the Dragons with a penalty.
But after controlling much of the second period, it was the Ospreys that sealed the victory through Ashley Beck's touchdown which moved them up to fifth in the table.
Looking to build on their dominant 32-3 success over the Llanelli-based Scarlets on Boxing Day, the visitors got off to the perfect start, going 7-0 up inside four minutes.
Good hands sent Walker away down the left wing, and although the youngster still had plenty to do, he finished impressively in the corner, Biggar converting.
However, the Dragons weren't allowing the Ospreys to dominate the contact area and duly hit back when Prydie converted a penalty opportunity.
The rest of the half remained scrappy with the away side proving the most dangerous with ball in hand, but they couldn't capitalise and the match remained finely poised at the break.
Although Steve Tandy's men controlled the early stages of the second period, they found it difficult to break down stubborn Dragons defence.
But their pressure eventually paid off when Lewis Robling was charged down and Beck had the simple task of collecting the ball and touching down under the posts.
Both teams pressed late on and had chances to score but it was the visitors that took the spoils.
Tries: Walker, Beck
Cons: Biggar 2
Dragons: 15 Hallam Amos, 14 Will Harries, 13 Pat Leach, 12 Andy Tuilagi, 11 Tom Prydie, 10 Lewis Robling, 9 Jonathan Evans, 8 Toby Faletau, 7 Nic Cudd, 6 Lewis Evans (capt), 5 Rob Sidoli, 4 Andrew Coombs, 3 Dan Way, 2 Sam Parry, 1 Phil Price.
Replacements: 16 Hugh Gustafson, 17 Owen Evans, 18 Nathan Buck, 19 Adam Jones, 20 Tom Brown, 21 Wayne Evans, 22 Steffan Jones, 23 Jack Dixon.
Ospreys: 15 Richard Fussell, 14 Ross Jones, 13 Tom Isaacs, 12 Andrew Bishop, 11 Eli Walker, 10 Dan Biggar, 9 Kahn Fotuali'i (capt), 8 Joe Bearman, 7 Sam Lewis, 6 Ryan Jones, 5 James King, 4 Lloyd Peers, 3 Adam Jones, 2 Richard Hibbard, 1 Ryan Bevington.
Replacements: 16 Scott Baldwin, 17 Duncan Jones, 18 Cai Griffiths, 19 Jonathan Thomas, 20 Morgan Allen, 21 Rhys Webb/Tom Habberfield, 22 Matthew Morgan, 23 Ashley Beck.
Referee: Nigel Owens