A late try from Tonderai Chavhanga saw the Dragons claim an 18-14 Pro12 victory over the Cardiff Blues at Rodney Parade on Thursday.
The Blues' play-off ambitions took a blow after Chavanga's individual try handed the hosts victory in the 72nd minute.
All the points in the first period came in the opening 20 minutes with Jevon Groves going over for Dragons to go alongside a conversion and a penalty from Lewis Robling.
Tom James responded for the Blues with an unconverted try with Dan Parks adding three more from the boot.
In the second half, Robling and Parks scored a penalty each before Ben Blair put Cardiff ahead, but Chavanga was the hero with his excellent late intervention.
Despite there being just two places between them at the start of the game, the teams were separated by 19 points. The Dragons have endured a disappointing year, winning just five of their RaboDirect Pro12 matches, and they fell behind here when Parks slotted an early penalty.
But the hosts struck back immediately when a poor pass by Michael Paterson was pounced on by Groves, who touched down. Robling added the conversion and then a further three-pointer as Newport led 10-3 after 14 minutes.
In an exciting opening quarter, the visitors hit back when Andy Tuilagi was stripped in the tackle before the ball was eventually fed out to James to scamper clear.
Robling and Parks traded second half penalties before James had a try disallowed.
However, Cardiff went ahead soon after when Blair struck a three-pointer. But when Chavanga took the ball out on the left wing, he chipped over the top, used his blistering pace before collecting and touching down for a superb score.
Tries: Groves, Chavhanga
Pens: Robling 2
Pens: Parks 2, Blair
Dragons: 15 Martyn Thomas, 14 Will Harries, 13 Andy Tuilagi, 12 Ashley Smith (c) 11 Aled Brew, 10 Lewis Robling, 9 Wayne Evans, 8 Tom Brown. 7 Darren Waters, 6 Lewis Evans, 5 Rob Sidoli, 4 Jevon Groves, 3 Nathan Buck, 2 Steve Jones, 1 Nathan Williams.
Replacements: 16 Sam Parry, 17 Phil Price, 18 Dan Way, 19 Hugo Ellis, 20 Hywel Stoddart, 21 Joe Bedford, 22 Tonderai Chavhanga, 23 Steffan Jones.
Cardiff Blues: 15 Chris Czekaj, 14 Harry Robinson, 13 Gavin Evans, 12 Dafydd Hewitt, 11 Tom James, 10 Dan Parks, 9 Richie Rees, 8 Xavier Rush, 7 Martyn Williams, 6 Michael Paterson, 5 Cory Hill, 4 Macualey Cook, 3 Scott Andrews, 2 T Rhys Thomas (c), 1 Sam Hobbs.
Replacements: 16 Ryan Tyrell, 17 John Yapp, 18 Ryan Harford, 19 Maama Molitika, 20 Josh Navidi, 21 Lewis Jones, 22 Ceri Sweeney, 23 Ben Blair.
Venue: Rodney Parade
Referee: Leighton Hodges (WRU)