Hook provided some of the few bursts of running rugby
Ospreys: (6) 12
Pens: Hook (3), Henson
Dragons: (3) 6
Pens: Sweeney (2)
The Ospreys did enough to edge victory against the dogged Dragons in dreadful conditions at the Liberty Stadium.
The visiting forwards were on top for much of the game, but James Hook punished them with three penalties.
Ceri Sweeney kept the Dragons in touch with two kicks, but indiscipline from Ian Gough allowed centre Gavin Henson to blast over a long-range penalty.
The Dragons kept battling, but a blown late Gough chance meant they had to make do with a losing bonus point.
It's taken me a while to get back to form after my injury, but there's a bit of momentum building now
Man-of-the-match Ryan Jones
After a dull start in swirling wind and driving rain in Swansea, it was predictably Hook who lit up the game.
A dazzling show-and-go in midfield opened up the Dragons' defence, then the outside-half's grubber kick through went just too far for the chasing Lee Byrne to convert.
With the outstanding Ryan Jones helping to fire the home side, Hook got the first points of the game with a penalty, while the visitors' front-row injury problems were compounded when Jamie Corsi limped off.
But Lee Harrison came on and helped destroy an Ospreys front row missing Duncan and Adam Jones to give Sweeney a penalty in front of the posts.
Close-combat exchanges dominated a scrappy game
He converted, but Adam Black took out Jason Spice off the ball, allowing Hook to give the home side a 6-3 lead at the break.
The Dragons brought Colin Charvis on for Jamie Ringer at half-time, but lost Harrison to the sin bin after a blatant offside at a ruck.
Hook landed the tricky penalty, cancelled out when Sweeney punished the Ospreys for hands in a ruck.
A superbly worked cross kick from Sweeney nearly resulted in a Kevin Morgan try, but Henson just did enough to make the full-back knock on.
The pressure from the visiting forwards went unrewarded, though, as two successive penalties conceded by Gough gave Henson the position to drill over a monster kick.
Gough had been inspirational all game with his tackling and driving play, but it was the unfortunate Wales lock who knocked on when an injury-time Paul Emerick break gave the visitors the chance to sneak victory.
Man-of-the-match Ryan Jones:
"The weather was pretty poor and it deteriorated, that was a good old-fashioned derby.
"The Dragons came here, fronted up, and made it difficult for us.
"It's one of those games where you have to be happy with a win, it could have gone the other way.
"It's taken me a while to get back to form after my injury, but there's a bit of momentum building now."
Ospreys: Byrne, Mustoe, Selley, Henson, Walker, Hook, Spice, James, B. Williams, Griffiths, Cockbain, A. Jones, Lloyd, Tandy, R. Jones.
Replacements: Connor for Selley (57), A. Bishop for Hook (81), Millward for Griffiths (45), Bateman for Lloyd (61), Tiatia for Tandy (52). Not Used: Shervington, Roberts.
Dragons: Morgan, Wyatt, Emerick, Smith, A. Brew, Sweeney, Cooper, Black, Daly, Corsi, Gough, Sidoli, Bearman, Ringer, Fitisemanu.
Replacements: Hercus for Morgan (81), Walker for Cooper (71), Crawford for Daly (73), Harrison for Corsi (33), Hall for Bearman (59), Charvis for Ringer (41), Owen for Fitisemanu(59).
Referee: Nigel Owens (WRU)