Exeter Chiefs took a huge stride towards Aviva Premiership safety as they overcame in-form Harlequins 20-6 thanks to a second-half try from Tom Johnson on Saturday.
Johnson struck immediately after the restart and fly-half Gareth Steenson weighed in with 15 points to put a dent in Quins' play-off hopes.
It was a sixth win of the season for Exeter, who have acclimatised in style to the demands of the top flight following their promotion last season.
Two penalties from Steenson put the Chiefs 6-0 ahead after 18 minutes but the visitors steadied themselves and hit back through a penalty from fly-half Nick Evans in the 21st minute.
However, the momentum remained with the hosts and two more penalties from Steenson put them 12-3 ahead at the break.
Moments after the restart, Johnson crossed the line following a move which summed up the confidence of Exeter's play.
The ball passed through several pairs of hands and culminated in centre Jason Shoemark giving the final pass to Johnson, who had to shrug off a tackle to score in the corner.
Steenson's conversion from the left touchline was wide of the mark.
A penalty from Evans gave Quins hope but Steenson booted his fifth-three pointer of the afternoon to secure Exeter a relatively comfortable win.
The hosts were forced to defend solidly but were prepared to mount another attack from deep in their own half in search of a second try to cap another memorable victory for the west country side.
Pens: Steenson 5
Pens: Evans 2
Exeter: 15 Luke Arscott, 14 Matt Jess, 13 Jason Shoemark, 12 Sireli Naqelevuki, 11 Nic Sestaret, 10 Gareth Steenson, 9 Haydn Thomas, 8 Richard Baxter, 7 James Scaysbrook, 6 Tom Johnson, 5 James Hanks, 4 Tom Hayes (capt), 3 Chris Budgen, 2 Neil Clark, 1 Brett Sturgess.
Replacements: 16 Chris Whitehead, 17 Ben Moon, 18 Hoani Tui, 19 Chad Slade, 20 James Phillips, 21 Junior Poluleuligaga, 22 Ryan Davis, 23 Phil Dollman.
Harlequins: 15 Mike Brown, 14 Gonzalo Camacho, 13 George Lowe, 12 Jordan Turner-Hall, 11 Ugo Monye, 10 Nick Evans, 9 Karl Dickson, 8 Chris Robshaw (capt), 7 Will Skinner, 6 Maurie Fa'asavalu, 5 George Robson, 4 Ollie Kohn, 3 James Johnston, 2 Joe Gray, 1 Joe Marler.
Replacements: 16 Chris Brooker, 17 Ceri Jones, 18 Mark Lambert, 19 Tomas Vallejos, 20 M Browne, 21 Dave Moore, 22 Rory Clegg, 23 Tom Williams.
Venue: Sandy Park
Referee: Tim Wigglesworth