Ulster beat the Dragons 20-13 on Welsh soil to book themselves a place in the Magners League semi-finals, where they will face rivals Leinster.
Two tries from Nevin Spence and another from Pedrie Wannenburg gave Ulster a 20-6 half-time lead, but the home side fought back through a Tom Riley score in the second period.
Leinster's victory over Glasgow meant Ulster finish in third, meaning the Ulstermen will be the away side for their semi-final.
The victory was Ulster's first win at Newport since 2006 and they got off to the perfect start as Ian Humphreys kicked the away side into the lead in the third minute.
Six minutes later and the contest saw its first try as Nevin Spence broke through the Dragons' defence and held off Steffan Jones to cross.
Spence scored his second on 21-minutes to put the Ulstermen in a commanding position. The centre was the quickest to react after Adam D'Arcy lost control of the ball as he attempted to score and burrowed over to make it 13-3.
Jason Tovey reduced the deficit to seven points, but Ulster soon troubled the scoreboard again. Wannenburg, moved to blindside flanker due to Willie Faloon's injury, took advantage of a mix-up in the Dragons defence and powered his way across the line. Humphreys added the easy extras to make it 20-6.
Ulster's dominance was challenged in the second half and with 20 minutes remaining the Dragons found their breakthrough.
Matthew Jones' clever flat-pass found Riley and the centre shrugged off two challenges to touchdown. The Dragons pushed to level the scores, but they could not force their way through the dogged Ulster defence.
Con: Jones, Tovey
Tries: Spence 2, Wannenburg
Dragons: 15 Stefan Jones, 14 Adam Hughes, 13 Tom Riley, 12 Pat Leach, 11 Aled Brew, 10 Jason Tovey, 9 Wayne Evans, 8 Toby Faletau, 7 Gavin Thomas, 6 Danny Lydiate, 5 Adam Jones, 4 Luke Charteris, 3 Dan Way, 2 Lloyd Burns, 1 Phil Price.
Replacements: 16 Tom Willis, 17 Hugh Gustafson, 18 Ben Castle, 19 Andrew Coombs, 20 Joe Bearman, 21 Matthew Watkins, 22 Jon Evans, 23 Mathew Jones.
Ulster: 15 Adam D'Arcy, 14 Craig Gilroy, 13 Darren Cave, 12 Nevin Spence, 11 Simon Danielli, 10 Ian Humphreys, 9 Ruan Pienaar, 8 Robbie Diack, 7 Chris Henry, 6 Pedrie Wannenburg, 5 Dan Tuohy, 4 Johann Muller, 3 Declan Fitzpatrick, 2 Rory Best (c), 1 Tom Court.
Replacements: 16 Andi Kyriacou, 17 Paddy McAllister, 18 Jerry Cronin, 19 Tim Barker, 20 TJ Anderson, 21 Paul Marshall, 22 Ian Whitten, 23 C Gaston.
Date: Friday, 6 May
Venue: Rodney Parade
Kick-off: 19:05 (18:05 GMT)
Referee: Alan Lewis
Assistant Referees: Tim Hayes, Sean Bricknell