The RBS 6 Nations Championship rendered both sides below strength for this league encounter at Rodney Parade but it was the Welsh youngsters and wily veterans who proved too strong for Leinster's young charges.
Kieran Lewis did show his potential with two well-taken tries, including a stunning length of the field score late in the game, but without their international players Leinster were fighting the Dragons' fire with a water pistol. It has been a turbulent time in the Valleys and nowhere have the remarkable goings on between the Welsh Rugby Union, the Wales team and Mike Ruddock been more keenly observed than here at his former region.
However Newport gave Welsh rugby a timely boost with victory over their Irish opponents, a week before Wales visit Lansdowne Road, and strike a significant blow to Leinster's title credentials given the defeats suffered by the top two, Munster and Edinburgh.
"It was a missed opportunity," conceded Cheika. "All the time in the Celtic League, you are not just playing the opposition but all the others teams as well. We let the pressure off ourselves to perform in this game and so we let the pressure off the top teams in the league.
"Sometimes you have win games, even when you're playing poorly. We were poor in this game but we got zero out of it and that's probably all we deserved. We failed to retain possession, we didn't go through any phases and so we got no momentum at all. We did have opportunities in good positions but we gave away too much ball and didn't build any sort of game. There were a lot of stoppages in the game and that played into Newport's hand but we have to hold our hands up and admit we were poor."
One of the lengthier stoppages was after Eric Miller took exception to being used as a doormat by the Newport forwards only to concede a penalty for his troubles. It set the tone for the rest of the game. Sensing his pack had the beating of Leinster, Dragons captain Jason Forster opted for a driving lineout and was duly rewarded with a try that saw Leinster trail 23-11 at half-time. When Forster grabbed his second midway through the second half after Leinster's efforts to shove their way over the line were thwarted, the game was beyond their reach.
"I wasn't happy about the stamping incident, they (Newport) almost ripped Eric's arms off yet they got the penalty. I was stunned but that was nothing to do win the game itself. You would have to say they out-muscled us and that was very disappointing."
Lewis at least managed to show some strength to burst through the last defender after catching Newport pressing for the bonus point with a sensational try under the posts.
Dragons: A Thomas; G Wyatt, N Brew, J Bryant, B Breeze; C Warlow (S Tuipulotu, 80), G Baber; A Black (D Maddocks, 62), S Jones, R Thomas, A Hall (B Griffiths, 62), P Sidoli, J Ringer, R Oakley, J Forster (capt).
Leinster: G Dempsey; R Kearney, K Lewis, J Hepworth, D Hickie; F Contepomi (capt), G Easterby; R Corrigan (R McCormack, 76), B Blaney, W Green, A Byrnes (B Gissing, 39-40, 62), B Williams, E Miller, J Heaslip (N Ronan, 56), K Gleeson.
Tries - J Forster (2), G Wyatt
Cons - C Warlow (2)
Pens - C Warlow (4)
Tries - K Lewis (2)
Con - F Contepomi
Pens - F Contepomi (2)
Referee: Peter Allan (Scotland)