Gloucester exploited Worcester full-back Melani Nanai's first-half red card as they ran in six tries to hammer the Warriors on the return of Premiership rugby to Sixways.
Warriors led 5-0 when England and Lions winger Jonny May was felled on 18 minutes by Nanai's no-arms tackle.
May did not return from a head injury assessment while Nanai was sent off.
Jack Singleton, Ollie Thorley (2), Louis Rees-Zammit, Jason Woodward and Stephen Varney got Gloucester's tries.
Thorley's were both created by Danny Cipriani, while May's replacement Rees-Zammit's score was the young Wales prospect's eighth in the Premiership, taking him clear as the league's leading scorer, and former Worcester hooker Singleton's came against his old club.
And it all came after young Warriors captain Ted Hill had scored inside two minutes, Warriors' other try coming from Scott van Breda late on.
The irony for Nanai was that he had actually been ruled out "for the season" with a shoulder injury in February and, but for the coronavirus outbreak, would not have been playing.
It was a very disappointing way for Worcester to restart as they followed their six straight losses prior to lockdown with a seventh. But, already with such a comparatively young, inexperienced side, the game was effectively decided by referee Christophe Ridley's decision to red card Nanai.
Gloucester had George Skiverton taking charge as head coach for the first time following the midsummer backroom reshuffle that took Johan Ackermann to Japan, and also led to the departure of director of rugby David Humphreys.
Two minutes to score
After 161 days of inactivity at Sixways, it was somehow inevitable that it would take just two minutes for Worcester to score their first try.
On the day he became the fourth-youngest skipper in the 24 seasons of Premiership history, at 21 years and 142 days, Hill quickly showed he is the sort of captain to lead by example as he crashed over in the right corner.
Warriors debutant Billy Searle missed with the kick and also with another long-range penalty before the incident that changed the game.
Twelvetrees slotted the resulting penalty from Nanai's indiscretion, yet Warriors' immediate response was a Searle penalty of their own to restore the home lead to five points after centre Ollie Lawrence's burst through the middle had set up their attacking platform.
But Gloucester levelled for the first time at 8-8 when Worcester old boy Singleton, in his first game on loan from Saracens, materialised in the right place at the right time to go in at the right corner, although Twelvetrees missed the kick.
That makes him the 13th player to score tries for two different Premiership clubs in the same season - but surely the first to do it on his debut, against his old club.
Warriors finally crack
Three minutes from half-time, Worcester were still in the contest. But it all changed either side of the break, thanks to two Cipriani-inspired tries for Thorley.
Gloucester truly cashed in on their man advantage on 37 minutes when Cipriani's cleverly executed looped pass into the overlap space allowed Thorley to trot in at the left corner.
Then, after Twelvetrees had converted for a 15-8 lead, the same combination worked again nine minutes after the restart as Thorley was first to pounce on Cipriani's crossfield kick, Twelvetrees again adding the extras via the post.
Gloucester then scored twice more in six minutes, through replacement winger Rees-Zammit, who had scored twice against Worcester at Kingsholm in December, and Jason Woodward.
They also had a sixth try ruled out for a double movement before 14-man Worcester scored again through Van Breda. But Gloucester had the last word to score again late on through another man off their bench, Varney.
Warriors director of rugby Alan Solomons told BBC Hereford & Worcester:
"The big factor was the red card. It would be wrong for me to comment on the decision as I've had not a chance to look it again properly but it clearly had a massive impact on the outcome.
"We gave them far too much momentum and didn't finish off the opportunities that we did create. But a red card always has a huge impact on any game and, once you're down to 14 men for almost the whole game, you've got problems.
"You've got to keep it all in perspective. We've really missed the crowd. They make a huge difference."
Gloucester head coach George Skivington:
"I haven't seen Jonny May since the game but it was a big collision and he had to come off.
"It was always going to be hard for the other team if someone is sent off but that wasn't my focus.
"I was just watching how our lads performed and our attitude under pressure and I'm happy with the effort from the boys."
Worcester Warriors: Nanai; Howe, Lawrence, Beck, van Breda; Searle, Hougaard; Waller, Annett, Schonert, Bresler, G Kitchener, Hill (capt), Lewis, Kvesic.
Replacements: Cutting, Holsey, Palframan, van Velze, du Preez, Simpson, Weir, Venter.
Gloucester: Woodward; Thorley, Harris, Twelvetrees, May; Cipriani, Simpson; Rapava-Ruskin, Singleton, Balmain, Slater, Clarke, Ackermann, Ludlow (capt), Polledri.
Replacements: Walker, Mulipola, Stanley, Garvey, Clement, Varney, Seabrook, Rees-Zammit.