Spirited Dragons produced a stunning first half performance but were ultimately edged out 26-21by Gloucester in a pulsating EPCR Challenge Cup encounter at Rodney Parade.
Wales international back row Taine Basham powered over before a stunning team score, finished expertly by Jared Rosser, had the home crowd off their feet as part of a thrilling opening 40 minutes.
Captain Harri Keddie also went over - after a sublime Sam Davies offload - as Dragons took a 21-12 lead into the break in front of the second biggest crowd of the season.
Gloucester, though, held firm at the start of the second half as the Men of Gwent looked to land a decisive fourth blow before turning to their power game.
Hooker Santi Socino was the beneficiary finishing with a hat-trick of tries from huge mauls as the English visitors took the spoils in the final pool game.
It left the home side to rue missed opportunities at the start of the second half, but with reasons for positivity ahead of a busy end of season finale and derby period.
With a partisan crowd in full voice under darkening skies, Gloucester showed their intent from the off as they kicked to the corner only for lock Will Rowlands to pinch the lineout.
There was however, no let off minutes later as a huge maul shunted over with hooker Socino the man to touch down.
With Jack Dixon and Harri Keddie to the fore, Dragons battled back and scored an impressive opener from Basham.
Dixon smashed up the middle before Basham took the ball on and splintered the defence as Elliot Dee ran a hard angle. The ball was recycled left and after patience build-up play it was Basham who bulldozed over.
Dragons were looking to play heads up rugby and a superb chip and collect from Davies sent them away again, with his sublime around the back pass to Gonzalo Bertranou breaking the field wide open.
The ball was spread left to the marauding Keddie who crashed into tacklers before flicking the ball to Rosser who showed great strength to get over to a thunderous cheer. Davies converted for a 14-7 lead.
The home lost the injured Greg Bateman just before the break and Gloucester struck for a second time with Rees-Zammit having an easy run in unopposed.
But it was Dragons who had the final word of the half and blew the roof off as, with time up, Davies beautifully cross kicked for Jonah Holmes to storm up the right.
The ball was taken in field for Davies to take the ball into contact and superbly offload to Keddie to race over to wild celebrations and a 21-12 lead at the break.
Dragons started the second half as they ended the first, Wainwright blowing a huge hole in midfield and racing 50 metres before the ball was sent left but found touch and not the hands to finish.
A penalty at scrum time gave the Men of Gwent another chance to strike but the ball again went to ground as the hosts looked to land a huge blow.
Adam Warren produced a great turnover on the floor, but scrappy ball saw Gloucester hack forward and then almost get in down the left after Ben Meehan spotted space.
The Cherry and Whites then turned to the maul once again and, after several penalties, referee Tual Trainini lost his patience and yellow carded Dee for repeated team offences.
Gloucester sensed the opportunity and got back into the game on 63 minutes, Socino grabbing his second of the night from another maul.
With the man advantage, Gloucester started to turn the screw and powered over again to give front row Socino a hat-trick of carbon copy scores.
David Richards made his debut in the final ten minutes – becoming Dragon No.312 in the process – but there was no final twist as the visitors held firm.
14m Socino t Barton c 0-7
20m Basham t Davies c 7-7
27m Rosser t Davies c 14-7
37m Rees-Zammit t 14-12
40m Keddie t Davies c 21-12
63m Socino t Twelvetrees c 21-19
68m Socino t Twelvetrees c 21-26
Dragons: Jordan Williams (Richards 69), Jonah Holmes, Adam Warren, Jack Dixon, Jared Rosser, Sam Davies, Gonzalo Bertranou (Williams 73); Greg Bateman (Seiuli 35), Elliot Dee (T. Davies 71), Leon Brown (Coleman 64), Joe Davies (Carter 59), Will Rowlands, Harri Keddie, Taine Basham (Fry 73), Aaron Wainwright
Replacements: Taylor Davies, Aki Seiuli, Chris Coleman, Ben Carter, Ben Fry, Rhodri Williams, Will Reed, David Richards
Gloucester: Kyle Moyle, Louis Rees-Zammit, Tom Seabrook, Billy Twelvetrees, Ollie Thorley, George Barton, Ben Meehan; Harry Elrington, Santi Socino, Kirill Gotovtsev, Freddie Clarke, Andrew Davidson, Jordy Reid, Harry Taylor, Ben Morgan
Replacements: Henry Walker, Jamal Ford-Robinson, Bryan O'Connor, Alex Craig, Ruan Ackermann, Charlie Chapman, Louis Hillman-Cooper, Santiago Carreras
Referee: Tual Trainini (France)