Rob Baxter’s men went into the clash trailing leaders Wasps by five points, but bridged that gap by running in five tries to Quins’ three.
Mathew Luamanu scored in the corner to give Quins the lead after good handling from the hosts and, though Henry Slade kicked a penalty and Dave Ewers went over for Exeter, the London club levelled with a Nick Evans penalty.
Michele Campagnaro’s try, converted by Slade, ensured Quins went into the break behind despite another penalty from Evans.
Evans re-established Quins’ lead after the break with a try and a penalty – separated by a three-pointer from Slade – but the visitors found another gear in the closing stages.
Lachie Turner chased down his own chip to put Chiefs back ahead and Slade gave Quins a mountain to climb by extending the advantage in similar fashion.
The game was all but over by the time Turner went over for his second, though Tim Visser crossed at the death for Quins.
Wasps will have a chance to restore their five-point lead when they take on Bristol on Sunday.
FULL TIME: Harlequins 26 Exeter Chiefs 39
Report and Reaction to follow shortly pic.twitter.com/6uqnDafZhQ
— Exeter Chiefs (@ExeterChiefs) April 14, 2017
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