After a slow start, the game was brought to life by a fine try from the Dragons when outside-half James Arlidge cut through a gap on the right and gave a pass to wing Aled Brew to storm home form 15 metres into the corner.
Ulster hit back when the Dragons infringed 30 metres in front of their posts, making the straight-forward kick easy for outside-half Ian Humphreys.
The Dragons restored their five point advantage when Arlidge struck a 25 metre penalty.
An Ulster onslaught, led by scrum-half Isaac Boss, near the home line failed to deliver any points.
During the first half Ulster’s forwards were turned over in the loose by the well drilled home eight and were bullied in the set-pieces.
Italian referee Carlo Damasco was busy with the whistle as the front rows went down time and again.
He eventually sent both Dragons loose-head prop Ali McKenzie and Ulster’s South African tight-head BJ Botha to the sin-bin.
But, after Arlidge and Humphreys added further penalties, the Dragons got an iron grip on the match.
A superb dash through the flaky Ulster half-backs by centre Tom Riley saw him link with full-back Jason Tovey and then with wing Richard Fussell for a great touchdown.
When hooker Steve Jones slammed into Humphreys as the outside-half tried to field a high ball, centre Ashley Smith was on hand to kick up field and drop on to score.
The match disintegrated into an error-strewn affair as the Welsh side were able to claim a comfortable victory.
Newport-Gwent D’gons scorers: Tries: Brew, Fussell, Smith. Cons: Tovey. Pens: Arlidge 2.
Ulster scorers: Pens: Humphreys 2.
NEWPORT-GWENT D’GONS: Tovey, Brew, Riley, Smith, Fussell, Arlidge, W. Evans, McKenzie, Willis, Hall, A. Jones, Charteris, Lydiate, G. Thomas, Bearman.
Replacements: M. Thomas for Tovey (78), S. Jones for Arlidge (62), Gustafson for Lydiate (41), Sidoli for G. Thomas (56).
ULSTER: Cunningham, Nagusa, Trimble, Whitten, Danielli, Humphreys, Boss, Young, Kyriacou, Botha, Tuohy, Caldwell, Henry, Faloon, Diack.
Replacements: Wallace for Cunningham (29), Cave for Nagusa (68), D. Fitzpatrick for Whitten (36), Marshall for Humphreys (68), Brady for Kyriacou (56), O’Donoghue for Henry (36), Anderson for Diack (68).
Referee: Carlo Damasco (Italy).