A late try from replacement prop Moray Low saw champions Exeter come from behind to secure a 20-18 win over rivals Saracens in a brutal clash at Allianz Park.
Rob Baxter's Chiefs trailed for the vast majority of the game after early scores from Alex Goode and Schalk Brits but produced a sterling second-half comeback to move five points clear at the top of the Aviva Premiership.
Saracens scrum-half and Exeter fly-half Gareth Steenson exchanged early penalties but it was the hosts who soon surged clear -- Goode swapping passes with Nathan Earle down the touchline before cruising in for the game's opening try.
Brits was next to score as the busy South African hooker -- subsequently withdrawn at half-time with what appeared to be a back injury -- burrowed under to touch down at a rolling maul; although the referee appeared to blow his whistle prematurely.
Steenson replied with a penalty but Exeter went into half-time frustrated once Olly Woodburn's attempts to force his way over in the corner were ruled unsuccessful by the television match official.
The visitors emerged with renewed purpose in the second period and were belatedly rewarded in the 51st minute -- Ian Whitten shrugging off Schalk Burger to surge over and begin the process of silencing the home crowd.
Marcelo Bosch casually blasted over a penalty from halfway soon after to settle Sarries' nerves to a degree but the sense of momentum shifting continued as the Exeter pack began to turn the screw in both set and loose.
With the clock winding down and their catch-and-drive system unfortunate not to have already yielded points, Exeter wheeled a maul from the corner to under the posts, where Low picked up from the base and sneaked under the bodies -- leaving Steenson the most simple of kicks for the lead.
A frantic finish followed as frayed nerves produced error after error but despite the urging of the crowd, Saracens were unable to push themselves into range for a match-winning kick.