Worcester full-back Melani Nanai was red carded only 18 minutes into Warriors' Gallagher Premiership return as Gloucester ran in six tries on their way to a 44-15 win.
Nanai crashed into Jonny May with a head-high shoulder charge 10 minutes out from the Worcester line, the Gloucester wing also seeing his game ended as he failed a subsequent head injury assessment.
Nanai's sending-off continued the Samoan's miserable first season for Worcester, a serious shoulder injury having sidelined him since early November.
An early try from Ted Hill put the hosts in front, but Nanai's red card proved a turning point as Gloucester ran riot.
Ollie Thorley scored two tries and Jack Singleton, Louis Rees-Zammit, Jason Woodward and Stephen Varney one apiece, with Billy Twelvetrees adding two penalties and four conversions.
Scott Van Breda scored a late consolation try for Worcester which Duncan Weir converted.
Worcester made a dream start, touching down within two minutes.
Playing with a penalty advantage, Billy Searle launched a speculative cross-field kick for Hill to collect a favourable bounce and score.
Searle missed the conversion and then a long-distance penalty, but Warriors continued to look the better side.
They could easily have had a second try when Nanai split the visitors' defence, but Tom Howe was unable to take a difficult pass.
Then came Nanai's dismissal, with Twelvetrees kicking the resulting penalty to leave Gloucester trailing 5-3 at the end of the first quarter.
Despite going down to 14, Worcester maintained their dominance and a splendid break from Ollie Lawrence secured his side a five-metre scrum.
From that position the visitors were penalised, allowing Searle to kick an easy goal.
Gloucester then responded with their first try when skilful passing sent Jake Polledri away down the right flank and, when the ball was recycled, former Warrior hooker Singleton was on hand to step inside two tackles and bring the scores level.
Minutes later the visitors went ahead when Twelvetrees and Polledri made telling bursts before a long pass from Danny Cipriani sent Thorley over, with a conversion from Twelvetrees giving his side a 15-8 half-time lead.
Eight minutes after the restart that lead was extended when a neat cross-field kick from Cipriani provided Thorley with a second before a driving line-out saw Joe Simpson provide Rees-Zammit with an easy run-in for the bonus point.
Worcester conceded a fifth when Woodward raced in from half-way before Warriors hit back as Van Breda opened his Premiership try-scoring account.
Gloucester, however, had the final say as replacement Varney darted over.
