A brilliant late solo effort from Dragons wing Rio Dyer was enough to give his side their first home win in 17 months as they beat Munster 23-17.
It was a dramatic finish to Dai Flanagan's first match at the helm, with director of rugby Dean Ryan absent.
Former Munster man JJ Hanrahan landed six penalties on his home debut.
Munster tries came from Stephen Archer and Ben Healy before the break, Healy adding seven points with the boot.
It was a performance to delight Dragons head coach Flanagan, with the side showing improvements in the set-piece and in defence.
Ryan's likely impending departure, after just over three years at the helm, followed an opening 44-6 defeat at Edinburgh which prompted him to make scathing criticism of the performance.
Dragons gave debuts to former London Irish lock George Nott in the starting XV plus Wales prop Rob Evans and ex-Bath centre Max Clark off the bench, among seven new recruits in the home squad.
Centre Steff Hughes, formerly under Flanagan at the Scarlets, was also part of pre-match preparations.
A decent Munster contingent and the presence of hundreds of noisy schoolchildren made for a raucous atmosphere despite some empty seats in the main stand after a winless 2021-22 at home.
The home supporters had plenty to cheer as Hanrahan knocked over five penalties, the last of them following a particularly impressive surge from all-action hooker Bradley Roberts, to one from Healy.
Munster suffered a double blow after 13 minutes when wing Keith Earls limped off and lock Jean Kleyn departed with a head knock, though former Scarlet Tadhg Beirne was a formidable replacement.
In a game of few early clear-cut chances, Munster struck twice in the last four minutes of the first half to turn a 15-3 deficit into a 17-15 lead.
They engineered the first try after 36 minutes when Healy put Simon Zebo away, and after Dyer was penalised and subsequently yellow-carded for a high tackle, giant prop Archer ploughed over from close range.
Healy converted that and his own score, darting over himself after scrum-half Craig Casey exploited a blind-side gap following a driving maul.
Neither side created much for most of the second period, and Dragons spurned a chance to retake the lead when Hanrahan pushed a 40-metre penalty shot wide with 10 minutes left.
A minute later, Dragons elected to run back a Munster clearance from halfway with Hanrahan and Angus O'Brien giving Dyer room to work in as he burst through three challenges to run in for a scorching score from inside his own half.
Munster had one further spell of pressure, but Dragons broke out and though they could not finish the chance, Hanrahan landed a sixth penalty to use up the final seconds of the game and spark the crowd's celebrations.
Dragons RFC: Angus O'Brien; Rio Dyer, Sio Tomkinson, Jack Dixon, Ashton Hewitt; JJ Hanrahan, Rhodri Williams; Aki Seiuli, Bradley Roberts, Lloyd Fairbrother, George Nott, Will Rowlands (capt), Sean Lonsdale, Taine Basham, Ross Moriarty.
Replacements: Elliot Dee, Rob Evans, Chris Coleman, Ben Carter, Aaron Wainwright, Lewis Jones, Max Clark, Jordan Williams.
Munster: Mike Haley; Keith Earls, Dan Goggin, Malakai Fekitoa, Simon Zebo; Ben Healy, Craig Casey; Dave Kilcoyne, Niall Scannell, Stephen Archer, Jean Kleyn, Fineen Wycherley, Jack O'Donoghue, Peter O'Mahony (capt), Jack O'Sullivan.
Replacements: Scott Buckley, Liam O'Connor, Keynan Knox, Edwin Edogbo, Tadhg Beirne, Paddy Patterson, Joey Carbery, Liam Coombes.
Referee: Sam Grove-White (SRU)
Assistant referees: Simon Rees & Aaron Parry (WRU)
TMO: Andrew McMenemy (SRU)