London Irish came from behind to beat Exeter and record their first league double over the Chiefs in 11 years.
Exeter led 14-0 after 20 minutes thanks to tries from Olly Woodburn and prop Patrick Schickerling.
But Matt Cornish went over and James Stokes added a try on the stroke of half time as the hosts began to take command and led at the break.
Irish had the better of the second half but could not extend the lead as Paddy Jackson missed a late penalty.
The win saw Irish move above Exeter and into sixth place in the Premiership as the Chiefs, who have finished in the top two in the last six Premiership seasons, slip further away from the play-off places.
Joe Simmonds' excellent break set up the field position for Woodburn to go over under the posts a few phases later for a fifth-minute lead before a well-executed 50-22 from the Chiefs fly-half saw Exeter pressurise Irish and force a tap penalty which allowed Schickerling to score his first try for the club.
But Irish began to hit their straps as Cornish forced his way over after pressure on the Exeter line and Jackson added two penalties.
Exeter had a chance of a third try shortly before the break but infringed and the Exiles were able to relieve the pressure before going up the other end and scoring when Stokes got on the end of a Ben Loader pass to dive into the right corner.
Irish also began the second half strongly and Exeter did well to keep the hosts out with some impressive defence.
The Exiles continued to turn the screw on the Exeter pack with an hour gone as the Chiefs conceded a host of penalties close to their line, but Irish failed to convert their territorial advantage.
Exeter had a great period of pressure with 10 minutes left but knocked on inside the Irish 22 - and Jackson missed a penalty with the final kick of the game in a scoreless second half.
London Irish: Stokes; Loader, Rona, Van Rensburg, Cinti; Jackson, Phipps; Goodrick-Clarke, Cornish, Hoskins, Simmons, Coleman, Rogerson (capt), Pearson, O'Brien.
Replacements: Willemse, Gigena, Van der Merwe, Munga, Cracknell, Martin Gonzalez, O'Sullivan, Rowe.
Exeter: Hogg; Woodburn, Whitten, H Skinner, O'Flaherty; J Simmonds (capt), J Maunder; Kenny, Innard, Schickerling, Gray, S Skinner, Ewers, Kirsten, Armand.
Replacements: Yeandle, Keast, Iosefa-Scott, Jenkins, Grondona, S Maunder, O'Brien, Hodge.
Referee: Matthew Carley (RFU).