Pat Lam described Bristol's stunning victory at Exeter as a "major marker" for the season after his side came back from a 17-0 half-time deficit to win 20-17 at Sandy Park.

Dan Thomas came on as a half-time replacement for the injured Jake Heenan and it was the 26-year-old flanker who was at the centre of a driving maul that crashed over the Chiefs' line in the last minute to snatch victory for Bristol and take them to the top of the Gallagher Premiership table.

Piers O'Conor scored the Bears' other try, with Callum Sheedy kicking two penalties and two conversions.

Director of rugby Lam said: "This victory is huge in our growth as we didn't beat Sale or Exeter last year so to beat both was a real learning curve for us and a major marker.

"Exeter are a power-reliant team and they were fully loaded today and to come here is a real mental and physical challenge.

"We didn't play our best rugby but we were top shelf in terms of attitude and commitment.

"We gave away soft tries in the first half so the message at half-time was to start from scratch, stick to our systems and build the scoreboard.

"We are proud to be top of the league but we are still gutted at throwing three points away at Harlequins."

Thomas said he was "over the moon" to help his side to the summit of the table but hailed Bristol's attitude and resilience.

"You have to challenge yourself when you come down here and when we went 17-0 down, our heads didn't drop," he said.

"Their points came from our mistakes but our offloading game worked better for us in the second half and we stuck to our systems.

"We were lucky to come out on top but I'm over the moon."

Exeter had built up a 17-0 lead through tries from Sam Simmonds and Nic White with seven points from the boot of Joe Simmonds, but Chiefs boss Rob Baxter was critical of his side's second-half performance.

He said: "We didn't do ourselves justice today as it was just basic sloppiness.

"We made silly mistakes and when the pressure came on as a result of Nic White's yellow card, we made some really odd decisions."

Both bosses was asked about their view on Saracens' fine and deduction of 35 points for breaching the salary cap.

Lam said: "It's all about having a level playing field and we would do anything like that as we do everything by the book.

"We have one of the richest owners in Steve Lansdown but we won't consider anything illegal and the rules are very clear about what you can and can't do."

Baxter added: "It's for other people to decide what Saracens' fate is and we and the other 10 clubs should just focus on themselves.

"Losing today was nothing to do with events off the field."