Winger Miles Benjamin has now equalled last season's 17-try haul
Miles Benjamin claimed a hat-trick as Worcester started their Championship play-off campaign with a comfortable victory at the Memorial Stadium.
Winger Benjamin ran in two tries in five minutes late in the first half to set Richard Hill's Warriors on the way against their coach's former club.
Bristol did manage two tries after the break in an ill-tempered game.
But Worcester ran in four more, through Marcel Garvey, hat-trick man Benjamin, Bruce Douglas and Joe Carlisle.
Victory came at a cost for Worcester, who lost former skipper Pat Sanderson in the second half with a dislocated shoulder, which now looks likely to rule him out for the rest of the season.
A string of yellow cards following an ugly flare-up, coupled with the sending off of home skipper Iain Grieve, meant that it was 12 against 13 at one point in the second half.
After two early penalties from Andy Goode, who was also to slot his two first-half conversions, Bristol did pull it back to 6-3 just five minutes before half-time.
But a mistake on the short side allowed Benjamin in and the winger struck again when he cashed in on Anthony Elliott's poor kick to go under the posts from the halfway line.
Bristol second row Mariano Sambucetti gave his side some hope when he scored Bristol's first try early in the second half.
I don't think I've ever seen five players off the field at the same time
Worcester coach Richard Hill
But the home side then came off worse from the outbreak of fisticuffs that sullied the contest 16 minutes into the second half.
While Goode and Kai Horstmann were sent to the sinbin, along with home number eight Dan Montagu, Grieve was given his marching orders.
And, when Ross Johnston was also sinbinned shortly afterwards, Bristol were at one point two men down.
Worcester cashed in when, after Garvey had scored from one wing, warriors top try scorer Benjamin completed his hat-trick - his 17th of the season.
And, although home winger George Watkins crossed to pull it back to 15-30, Worcester had the last word, running in two more late tries through Douglas and Carlisle.
Worcester captain Chris Pennell, starting at full-back in only his fourth game after recovering from a broken ankle, missed his two pots at goal. But Carlisle added the final two conversions.
That completed Worcester's third win this season against Bristol.
They won 38-20 at Sixways in October before repeating that when they came from 20-5 down to win 42-23 at the Memorial Stadium in January.
They will meet for the fourth and final time at Sixways in next month's final play-off group game.
Bristol head coach Paul Hull told BBC Radio Bristol:
"We gifted them three tries. That's 21 points and you can't do that against this team.
"And obviously our ill-discipline contributed to that as well with yellow cards and red cards being shown.
"I didn't see the incident. There were a few fracas but I was looking at the ball. The referee stood back, there were a few groups of fights so I can't comment on it as I didn't see too much, but I've got good faith in Dean Richards and his team. He managed a feisty game well.
"What I was pleased about was our physicality and our attitude was spot on. But we need to match that with cool heads and being clinical with a clear mind and at times we were off the page."
Warriors coach Richard Hill told BBC Hereford and Worcester:
"At half time we were 20-3 up, which was a big improvement on the last time we came here, although Bristol had the majority of the ball in the first half.
"Bristol had 70% of the possession and went through phase after phase but we kept our discipline.
"We did take a couple of chances, they then got back into the game and we had the fisticuffs.
"I don't think I have ever seen five players off the field at the same time.
"We have been through a very hard, physical game but we took our chances and our wingers were on fire."
E-mail this to a friend 
Printable version 
~RS~a~RS~Domestic~RS~q~RS~~RS~z~RS~41~RS~" height="1" width="2" alt="" /></p loading=)
Bookmark with:
What are these?