Harlequins have bounced back from their first Aviva Premiership defeat of the season last week to beat Exeter 11-9 on the road.
Scrum-half Danny Care scored inside the first three minutes to put Harlequins ahead by five, before Chiefs fly-half Ignacio Mieres kicked two penalties to take a slender one-point lead into the break.
Opposite number Rory Clegg kicked the travellers back into the lead on the 40-minute mark, before both sides made several substitutions on either side of the hour.
Chiefs substitute Gareth Steenson's late penalty momentarily put the home side back in front, before Clegg responded by kicking his second penalty of the day to retake the lead in the final three minutes.