Aneurin Owen marked his first start in 20 months with a try but Dragons long wait for a victory over league heavyweights Leinster continued in the BKT United Rugby Championship.
Owen - starting for the first time since March 2022 after injury torment – grabbed a second half try in a soggy encounter at Rodney Parade.
But it was Leinstermen – who had not lost three in succession on their travels since 2016 – who eased to the bonus point with tries from Dan Sheehan, Thomas Clarkson, Ciaran Frawley, Charlie Ngatai and Scott Penny.
Dai Flanagan’s men showed plenty of endeavour and enjoyed success with a well drilled maul in a closely fought first half.
However, in wet conditions it was the Irish province who wrapped up the win with a red card to Taine Basham compounding home misery.
Dragons made nine changes to the side that lost to Munster, with Wales internationals Aaron Wainwright, Elliot Dee, Rio Dyer, Dan Lydiate and Taine Basham all making first appearances of the season at home.
In driving rain that created a greasy surface, it was Dragons who got the home crowd going with a big early tackle from Aneurin Owen and turnover from Jared Rosser.
Tempers flared at the first scrum of the game as Leinster won a series of set piece penalties to kick to the corner.
The driving maul was looming large, and Dragons could find way to stop Ireland international Dan Sheehan from dotting down at the back of a huge shunt.
Cai Evans freed Reed into space with a neat delayed pass, as the Men of Gwent looked to respond, before the full back was on target with his first penalty of the afternoon to cut the lead.
The home side were enjoying plenty of territory with Owen- on his first start in 20 months - kicking deep after lost ball from Leinster, with Rosser tearing down the left wing but just beaten to the ball.
The home maul was causing Leinster issues as the forwards worked up field before Dyer kicked in behind for Rosser to again pressure Tommy O’Brien.
The scrum was hurting Dragons as Leinster again won a penalty to relieve any home pressure that was being built.
Lydiate soared high to steal lineout ball in front of the Compeed Terrace before Leinster again secured a penalty on halfway and menacingly kicked to the corner before knocking on.
The ever-alert Rhodri Williams showed his game awareness to race back and take the mark as the Irish province kicked in behind.
Dragons were working hard to limit Leinster opportunities but a quick tap from scrum half Ben Murphy saw the visitors race up close and win the scrum put in.
With time almost up in a tight first half, Leinster opted to take a tap penalty and tighthead Thomas Clarkson bulldozed over for a 14-3 lead at the break.
Leinster struck for a third time 58 seconds into the restart as they pounced on lost possession and clinical wen 60 meres through the hands to send full back Frawley over.
Dragons needed a response with Evans kicking in behind Leinster and then forcing a knock on as he chased his kick with early replacement Ewan Rosser.
The home side were pinned in the Irish half, but they could find no way past a physical and well-oiled defence that repelled wave after wave of attack.
Mounting pressure finally told as Williams kicked in behind a Leinster defence, that was flying out, and centre Owen won the race to dot down, awarded after a lengthy TMO check.
Leinster looked to respond and were close when Joe McCarthy was held up on the hour, courtesy of a combination of Rhodri Jones and Matthew Screech.
But they wrapped up the bonus point when centre Charlie Ngatai touched down, despite cries for a forward pass in the phase before.
Another lengthy stoppage for the TMO saw referee Gianluca Gnecchi send Taine Basham off for head contact.
And it went from bad to worse with Screech then yellow carded for a head-on-head collision minutes later as he looked to halt Rob Russell.
With a two-man advantage, Leinster looked to take advantage, but had to wait until the final seconds when Scott Penny powered over from close range.
Timeline:
09m Sheehan t R. Byrne c 0-7
15m Evans p 3-7
39m Clarkson t R. Byrne c 3-14
41m Frawley t R. Byrne c 3-21
50m Owen t Evans c 10-21
62m Ngatai t 10-26
80m Penny t R. Byrne c 10-33
Dragons RFC: Cai Evans, Rio Dyer, Steff Hughes (Dixon 76), Aneurin Owen, Jared Rosser (E. Rosser 43), Will Reed, Rhodri Williams (Blacker 65); Rhodri Jones (Seiuli 63), Elliot Dee (Benjamin 63), Lloyd Fairbrother (Yendle 63), Matthew Screech, George Nott, Dan Lydiate (Lonsdale 68), Taine Basham, Aaron Wainwright (Woodman 50)
Replacements: James Benjamin, Aki Seiuli, Luke Yendle, Sean Lonsdale, Ryan Woodman, Dane Blacker, Jack Dixon, Ewan Rosser
Leinster Rugby: Ciarán Frawley, Tommy O’Brien, Jamie Osborne, Charlie Ngatai, Jimmy O’Brien, Ross Byrne, Ben Murphy, Jack Boyle, Dan Sheehan, Thomas Clarkson, Joe McCarthy, Jason Jenkins, Ryan Baird, Will Connors, James Culhane
Replacements: Lee Barron, Paddy McCarthy, Michael Ala’alatoa, Max Deegan, Scott Penny, Cormac Foley, Harry Byrne, Rob Russell
Referee: Gianluca Gnecchi (FIR)
Attendance: 4,555
