The Dragons handed Ulster their third successive home defeat by earning a deserved 28-21 success at Ravenhill.
Ulster (6) 21:
Tries: N Best, McCormack.
Con: Humphreys 1.
Pens: Humphreys 3.
Dragons (3) 28:
Tries: Morgan, Black, Brew.
Con: Sweeney 2.
Pens: Sweeney 3.
Ulster led 6-3 after a scrappy first half with David Humphreys notching two penalties for the first side and Ceri Sweeney hitting the Dragons score.
Kevin Morgan's 43rd minute try set the tone for the second half and further tries from Adam Black and Nathan Brew kept the Dragons in control.
Tries from Ronan McCormack and Neil Best were not enough for the home side.
The Dragons made the better start against an Ulster side looking to get back to winning ways at Ravenhill.
Dragons pressure yielded a 10th minute penalty inside the '22 which Ceri Sweeney comfortably slotted between the post.
The remainder of the first period was exceptionally scrappy with Ulster having plenty of possession but having no attacking option other than David Humphreys' kicks for the corner.
A Humphreys penalty shaved the upright in the 26th minute but the Irish fly-half did level matters three minutes later after another Dragons infringement.
In the 32nd minute, Ulster, already without Andy Ward and Neil McMillan, received a further backrow blow when Roger Wilson was forced to leave the field through injury with Matt Mustchin introduced.
A minute later, Humphreys completed the first half scoring with a penalty which put Ulster 6-3 ahead at the break.
Tyrone Howe saw little of the ball in the game
However, the home lead didn't last long in the second half with Dragons full-back Kevin Morgan running through unopposed from the edge of the Ulster '22 for a try after some shocking defending.
Sweeney's conversion increased the visitors' lead to 10-6.
Penalties at either end from Humphreys and Sweeney maintained the Dragons' four-point advantage as the match neared the hour-mark.
Ulster then regained their lead after Tyrone Howe had produced the home side's first decent back move of the match.
The Ireland wing ran 80 yards to the edge of the Dragons '22.
The Dragons appeared to have regrouped to avert the danger but Humphreys' clever high kick towards the other corner resulted in Neil Best notching a touchdown.
However, Ulster's lead lasted less than five minutes with replacement Adam Black crossing the line to put the Dragons 18-14 ahead after the visitors had opened up the home defence.
Any hope of an Ulster comeback was effectively ended in the 72nd minute when Dragons winger Nathan Brew waltzed through the home defence to extend the lead to nine points.
Sweeney's conversion increased the advantage to 25-14.
Ulster produced a late rally and Ronan McCormack's injury-time try, converted by Humphreys, may have strained Dragons nerves.
However from the re-start, the Dragons won a soft penalty which Ceri Sweeney slotted over to conclude the match at 28-21.
"Ulster played well and their 10 [David Humphreys] made it hard for us by kicking us into the corners," said Dragons coach Chris Anderson.
"But we kept our composure and stayed tough and I was really pleased with our second-half effort."
Ulster: B Cunningham; T Bowe, P Steinmetz, K Maggs, T Howe; D Humphreys (capt), K Campbell; S Best, P Shields, R Moore, G Longwell, M McCullough, C Feather, N Best, R Wilson.
Replacements: N Brady, R McCormack, R Frost, M Mustchin, N Doak, P Wallace, J Bell.
Dragons: K Morgan; G Wyatt, P Montgomery, S Tuipulotu, N Brew; C Sweeney, G Cooper; R Snow, S Jones, R Thomas, I Gough, M Owen, J Ringer, J Forster, R Bryan.
Replacements: J Richards, A Black, G Robinson, P Sidoli, R Beattie, S Winn, G Baber.
Referee: Malcolm Changleng (Scotland)