Henry Slade's last-gasp try ignited wild celebrations as Exeter registered their first success at StoneX Stadium for eight years with a 30-24 victory over Saracens.
The Chiefs recovered from going 12-3 and 24-13 behind in a display of resilience as the Gallagher Prem title rivals fought out a gripping heavyweight collision in north London.
Number eight Greg Fisilau's two tries in the final quarter gave them hope and then the lead but they still had to withstand a Saracens attack consisting of 24 phases before Slade struck on the stroke of full-time.
Owen Farrell was presented with a 75th-minute penalty attempt that would have nudged the hosts 27-25 ahead, but his kick sailed wide of the left post.
England centre Slade impressed and his late try that put the icing on the cake provided redemption after he had gifted the Saracens the opening touch down with a pass that was intercepted by Noah Caluori for the opening try.
On the other wing, Max Malins was the next to score when he was presented with an easy run after Saracens peeled down the blindside from a line-out drive, with Theo Dan supplying the final pass.
Saracens threatened from another line-out drive, eventually going wide where Caluori strayed into touch.
In defiance of the 12-3 scoreline, Exeter were still giving as good as they got and only a yellow card shown to Tom Hooper for a dangerous clear out prevented them from crossing the 26th minute.
The Chiefs rallied magnificently from being a man down, renewing their attack with the help of some below-par kicking by Farrell.
Caluori produced a rare moment of fallibility in the air by completely missing a Harvey Skinner bomb under pressure from Campbell Ridl and the ball bounced off the Exeter wing's head and into his hands. A pass later and Stephen Varney was over.
Early in the second half Ridl was sent to the sin-bin for a deliberate knock-on just as Saracens were about to score in the right corner with Hartley looking to find Caluori, resulting in a penalty try.
Saracens found an extra gear for their most impressive attack of the game in the 56th minute with Malins and Tom Willis prominent until Elliot Daly sent Caluori racing over.
The mettle shown by Exeter this season was on display as they hit back with a powerful line-out drive that ended with Fisilau touching down.
And in the 69th minute they were over for the third time with Slade's beautiful pass sending Dafydd Jenkins rampaging down the left wing until Fisilau arrived to provide extra momentum that ended with the number eight charging over.
Farrell sent his penalty wide and once a late Saracens surge had been repelled, Slade picked up the ball dropped by Ben Earl and sprinted home as Exeter's squad celebrated in the dugout.
