Evans crossed from close range in the 62nd minute to make it 21-16 and round off a highly successful week for the Dragons following their home win over basement rivals Aironi. Those eight points moved them up to ninth, while the Ospreys have now slipped to seventh.
With 14 stars on international duty with the Wales national side, Ospreys forwards coach Jonathan Humphries spoke of the responsibility on his young side’s shoulders to continue the reigning holders’ assault on the celtic crown. But a second-string Ospreys side, still boasting 10 capped players in their squad, came up short as the spirited Dragons claimed a well deserved win.
But while scrum half Evans’ try was crucial in the end, it was a first half try from Wales Under 20 No 8 Toby Faletau that brought the game to life and gave the Dragons the belief they could go on and win. That score gave the visitors an 8-3 interval lead, but the Ospreys struck back through a Gareth Owen touchdown.
Jason Tovey struck the first blow for the hosts in the 12th minute with the opening penalty. But in an error strewn opening quarter it was the Ospreys who applied the most pressure.
A fired-up Richard Fussell came close to scoring against his former club while Owen squandered another opportunity in the slippery conditions.
Fly-half Dai Flanagan, who was handed his competitive debut for the hosts after signing from Cardiff Blues in the summer, pulled the Ospreys level shortly after the half hour mark.
But the Dragons instantly struck back in the 33rd minute as Faletau showed why he is so highly-rated by Wales boss Warren Gatland by bursting through the heart of the Ospreys defence.
Fellow back-rower Gavin Thomas made the initial inroads and offloaded to the rampaging Faletau who handed off Owen and Fussell to score in the corner.
Flanagan could have cut the deficit with three minutes to the interval but pushed his kick wide as the Dragons held a slender 8-3 lead.
But Fussell and Owen made amends for their earlier poor defence by linking up to bring the hosts level within two minutes of the restart.
Wing Fussell displayed his pace on the outside and passed inside to send Owen over beneath the posts. Flanagan converted to give the Ospreys the lead for the first time. Tovey and Flanagan exchanged further penalties until Evans sniped over to score.
Adam Hughes, Tom Willis and flanker Thomas were all involved in the build-up before the ball was recycled for Evans who dived over. Tovey converted and exchanged another set of penalties with Flanagan as the Dragons held on for a historic triumph in Swansea.
