Worcester beat Exeter for the first time since 2004 with a bonus point victory at Sixways to keep their Anglo-Welsh Cup hopes alive.
After 12 consecutive defeats at the hands of the Chiefs, the far more experienced Warriors made hard work of subduing their opponents after giving them a 14-point start.
Josh Adams scored two of their tries in the 31-21 success, with Luke Baldwin, Tom Howe and David Denton getting one each and Jamie Shillcock converting three.
Exeter, whose qualification for the next round is now out of their hands, responded with tries from Shaun Malton, Tom Lawday and Harry Strong, with Joe Simmonds adding three conversions.
The Chiefs took a third minute lead after the hosts lost possession on halfway. Tom O'Flaherty broke away before being hauled down by Matt Cox - but the ball was recycled for Lawday to score.
Much of the early play involved aimless kicking before Exeter extended their lead when from a line-out on the Worcester 22, weak tackling from Warriors gave Strong the chance to force his way over. Simmonds again added the conversion to give his side a 14-0 lead at the end of the first quarter.
Exeter were regularly infringing but Warriors declined to take a number of kickable penalties before the home side were rewarded when a clever cross-field kick from Shillcock was collected by Dean Hammond, who sent the supporting Adams over.
Chiefs' lock Ollie Atkins was sin-binned for offside at a driving maul and Worcester soon took advantage with Hammond's strong run setting up a try for Denton. Shillcock's conversion left his side trailing 14-12 at the interval.
Worcester skipper Donncha O'Callaghan was replaced at half-time by half-time by new signing Anton Bresler, before Atkins returned from the sin-bin.
However it was Warriors who took the lead for the first time when the best move of the game saw Howe race over after good contributions from Gareth Milasinovich and Shillcock.
Exeter regained their advantage when from a line-out on the home 22, replacement hooker Malton brushing away a weak tackle from Darren Barry to score.
That try was against the run of play as the Worcester pack dominated the second half - and they were rewarded with their bonus try when a Denton burst set up a second for Adams.
Chiefs' replacement Wilhem van der Sluys was then yellow-carded for a high tackle, allowing Baldwin to seal victory with a last minute try.