Gareth Wyatt led the way for the Dragons as they turned on the quality to beat visitors Leinster.
Dragons: (16) 34: Tries: Wyatt 2, Cooper, Morgan. Con: Sweeney. Pens: Sweeney 4.
Leinster: (10) 13: Try: Horgan. Con: Contepomi. Pens: Contepomi 2.
The flying wing claimed two tries and made the break late in the second half that led to Gareth Cooper's touchdown.
Full-back Kevin Morgan was also outstanding, claiming a fourth score in injury time to claim a bonus point.
Leinster had their Ireland players available for the first time, but were limited to Shane Horgan's try and eight points from Felipe Contepomi.
After an early exchange of kicks, the Dragons kept the ball in hand with good effect for the game's opening try to delight the Rodney Parade fans.
Full-back Morgan created the extra man out on the right and his pass sent Wyatt sliding in at the corner flag.
Leinster soon hit back, however, Brian O'Driscoll having the presence of mind to hack on a loose pass for Horgan to follow up and touch down.
Contepomi added the conversion and soon after struck his first penalty of the night, stretching the visitors' lead to five points midway through the first half.
The Welsh side responded by moving up through the gears and the phases, stretching Leinster left and right to get within five yards of the try line.
Only a crunching tackle from O'Driscoll stopped Sione Tuipulotu in his tracks, but an earlier infringement allowed fly-half Ceri Sweeney to slot a penalty.
Trailing by two points, the Dragons retook the lead by carving Leinster open down the visitors' left flank once again.
Morgan skidded a kick through and Wyatt again showed his raw pace and finisher's instinct, pouncing on the ball as opposite number Gary Brown hesitated.
Sweeney missed the extras but made no mistake with a penalty to give the Dragons a 16-10 lead at the break.
Both sets of players contributed to an absorbing first period, helped by the consistent and clear refereeing of Rob Dickson.
Contepomi kept up his 100% kicking record with a penalty for Leinster soon after the restart.
But it took until the 69th minute for the next score, Sweeney slotting his third penalty to restore the Dragons' six-point lead.
Typically after waiting so long for a score, another one came along almost immediately.
Sweeney's fierce defence forced Leinster into giving away another penalty, which the Dragons fly-half kicked with glee.
Crucially that took the Welshmen two scores clear, but the Dragons wrapped the game up in style with two minutes remaining.
Dragons skipper and No 8 Michael Owen passed superbly out of the tackle to find Wyatt cutting in off his wing.
The try line was beckoning for his hat-trick, but Wyatt sensed the Irish tacklers bearing down on him and unselfishly gave the scoring pass to scrum-half Cooper.
Morgan rounded off a perfect night for the Dragons deep in injury time, crossing for a deserved try that earned the home side a bonus point and allowed Sweeney to kick his first conversion of the night.
Dragons: K Morgan; G Wyatt, P Montgomery, S Tuipulotu, N Brew; C Sweeney, G Cooper; R Snow, S Jones, R Thomas, I Gough, P Sidoli, R Bryan, J Ringer, M Owen (capt).
Replacements: J Richards, A Black, C Anthony, R Beattie, R Oakley, S Winn, G Baber.
Leinster: D Hickie; S Horgan, B O'Driscoll, C Warner, G Brown; F Contepomi, G Easterby; R Corrigan (capt), S Byrne, R Nebbett, M O'Kelly, B Gissing, E Miller, S Jennings, V Costello.
Replacements: P Coyle, G Hickie, C Potts, D Dillon, M O'Meara, K Lewis, D Quinlan.
Referee: Rob Dickson (Scotland)