|Exeter (17) 17|
|Tries: S Simmonds, White Cons: J Simmonds 2 Pen: J Simmonds|
|Bristol (0) 20|
|Tries: O'Conor, Thomas Cons: Sheedy 2 Pens: Sheedy 2|
Dan Thomas' injury-time try completed a remarkable second-half turnaround as Bristol came from 17-0 down to beat Exeter and go top of the Premiership.
Thomas touched down with the clock in the red as Bristol scored 20 unanswered points to take victory at Sandy Park.
Exeter dominated the first period and had a commanding half-time lead after tries from Sam Simmonds and Nic White.
But Piers O'Conor's try and the boot of Callum Sheedy reduced the gap to four before the dramatic late Thomas winner.
Exeter started the game strongly with Stuart Hogg and returning England centre Henry Slade prominent with ball in hand.
Slade was stopped short after an excellent scything run before the ball was recycled to Simmonds who crashed over for the opening try after 15 minutes.
Australia scrum-half White added a second six minutes later after spotting a gap in the Bears defence and darting past hooker Harry Thacker.
Joe Simmonds converted both to maintain his 100 per cent kicking ratio in this year's Premiership.
A Sheedy penalty after 42 minutes got Bristol on the scoreboard, before 15-cap All Black Steven Luatua made an excellent try-saving tackle on Exeter's Alex Cuthbert.
Sheedy's second penalty came after 59 minutes and Chiefs scrum-half White was yellow-carded for a deliberate knock-on a minute later, as Bristol's confidence grew.
Their first try came after a good offload from Nathan Hughes to winger Luke Morahan, who beat Jack Nowell for pace and passed inside for O'Conor to cross.
As the clock ticked down, an Exeter infringement allowed Bristol to kick into the corner and set up a drive from the line-out.
The drive rumbled over the line and referee Karl Dickson consulted the television match official before ruling that Thomas had grounded the ball and sent Bristol top of the table going into the European break.
Bristol Bears director of rugby Pat Lam told BBC Radio Bristol:
"I'm very proud of the guys, it wasn't our best rugby but we were top around attitude, commitment, staying together as a team and culture.
"Coming to Exeter is a mental, physical challenge. You have to meet them physically but the mental side to stay as a team is key. Their game over 11 years has been built on trying to fatigue you so you make errors and they pounce.
"We did that in the first half. Our errors and discipline allowed them into the game and we gave away two soft tries. At half-time I asked for two deep breaths and for us to start from scratch.
"The only way back from 17-0 down is in game-plan, teamwork and systems. If we do individual things we come unstuck, but we had to build the scoreboard and the boys did it brilliantly."
Exeter head coach Rob Baxter told BBC Radio Devon:
"It's frustrating because first we got sloppy in the second half and then we got stupid.
"Really, I could stand here now and pick out five or six individuals and say 'Why did you do that?' and I don't even know if they would know now. We're looking and seeing things that aren't there.
"With 45 seconds left on the clock, we had managed to weather the storm and only needed to have two rucks, but we play and we get turned over. It's incredibly baffling."
On the off-field impact of the past week's Saracens issues
"If off-field matters did have an effect, it's excuses. Did it affect Bristol? Well they came back and won the game late on.
"There are 11 other clubs in there and it's going to affect everyone slightly differently.
"But the mark of a good rugby club, of good players and good coaching is that you get over it quickly and you move on. That's what we've got to make sure we do."
Exeter: Hogg; O'Flaherty, Slade, S Hill, Cuthbert; J Simmonds, White; Hepburn, Yeandle (capt), Williams, Kirsten, J Hill, Vermeulen, Kvesic, S Simmonds
Replacements: Cowan-Dickie, Keast, Street, Lonsdale, Armand, Maunder, Steenson, Nowell
Bristol: C Piutau; Morahan, Hurrell, S Piutau, O'Conor; Sheedy, Randall; Woolmore, Thacker, Afoa, Attwood, Vui, Luatua (capt), Heenan, Hughes.
Replacements: Capon, Y Thomas, Thiede, Holmes, D Thomas, Uren, Lloyd, Fricker.
Referee: Karl Dickson (RFU)