|Bristol (19) 29|
|Tries: Piutau, Morahan Cons: Sheedy 2 Pens: Sheedy 5|
|Exeter (12) 31|
|Tries: Low, Lawday, Cordero, Yeandle, Penalty Cons: Steenson 2|
Exeter Chiefs snatched a dramatic late win against Bristol Bears as they were awarded a penalty try in added time.
Referee Greg Macdonald ruled Bears had illegally brought down a rolling maul, which saw Chiefs come back from 26-12 down early in the second half.
Charles Piutau had earlier marked his Premiership debut for Bristol with a try alongside winger Luke Morahan.
Moray Low, Tom Lawday, Santiago Cordero and Jack Yeandle all crossed to help Exeter return to the top of the table.
Their scores secured a bonus point even before the controversial finale which denied Bristol a first victory over Exeter in any competition since December 2009.
Bears looked well on course for a third home win since their return to the top flight as fly-half Callum Sheedy slotted over five penalties and two conversions and Piutau and Morahan scored either side of half-time.
But Exeter's doggedness kept them in the game as Argentina winger Cordero weaved his way through space for a solo try and hooker Yeandle combined with Don Armand at a line-out to close the score to 26-24.
Sheedy's fifth penalty with four minutes to play looked to have secured a famous Bristol win, but hearts were broken when the Exeter pack rumbled over the line for the decisive moment and their seventh win in seven league games.
The Chiefs edge back ahead of Saracens, who have also won all their league games this season, on points difference.
Bristol head coach Pat Lam told BBC Radio Bristol:
"It was a great game of rugby. I thought both teams played some outstanding stuff with real physicality and it was a real test.
"We'll take a lot of confidence and it's great for the guys. But for a game and a contest to come down to a single decision like that, it's not great.
"There's no precedent set for it and it's just hugely disappointing for the whole group for the decision to go against us.
"But, we have to put it behind us and regroup with a short turnaround to the next game at Wasps. We're disappointed, but proud of the effort."
Exeter director of rugby Rob Baxter told BBC Radio Devon:
"We've got to move beyond the emotions of winning and losing for both teams and talk about what's really pleasing for us.
"However we've kind of done it, we've found a way of coming away and winning a very important game of rugby with five points.
"That's a very precious thing for us so I'm going to focus on the positives that worked for us.
"We weren't perfect, but that should be no excuse for the effort we put in. All I've done in the changing room is congratulate the guys for finding a way to win."
Bristol: Piutau; Morahan, O'Conor, Hurrell, Edwards; Sheedy (co-capt), Uren; Y Thomas, Malton, Afoa, Holmes, Muldowney, Luatua (co-capt), D Thomas, Haining.
Replacements: Lindsay, Woolmore, Thiede, Joyce, Smith, Randall, Eden, Bedlow.
Sin-binned: Sheedy (82 mins).
Exeter: Dollman; Cordero, Whitten, Devoto, Cuthbert; Steenson, Townsend; Low, Yeandle (capt), Holmes, Atkins, Lees, Armand, Kvesic, Lawday.
Replacements: Taione, Keast, Street, Van der Sluys, Dennis, White, Simmonds, Hill.
Referee: Greg Macdonald.