London Irish leapfrogged Exter in the Aviva Premiership standings on Tuesday thanks to a 29-22 victory at Madjeski Stadium.
The result sees Irish provisionally move into third position on the table.
Exiles held a 19-9 first half advantage, predominantly through the boot of Tom Homer, who kicked four penalties and converted Joe Ansbro's try.
Ignacio Mieres scored all of Exeter's points in the opening period and continued his fine form in the second half, converting Luke Arscott's touchdown and adding two more three-pointers.
But it was Shontayne Hape's score which proved decisive and took the hosts back into the play-off positions.
Despite a dip in form in October and early November, the Chiefs have hit back superbly in the past month, winning their previous five matches.
But they got off to the worst possible start when Ansbro scampered over for an early score. Started by England reject Topsy Ojo, the winger shrugged off the attentions of Matt Jess before off-loading to Declan Danaher who sent the centre away.
Mieres responded for Exeter with a penalty, although Homer restored Irish's seven point advantage with one of his own. The hosts' winger added two more three-pointers to make the score 16-3 after 26 minutes.
But Exeter are stubborn opposition for any side and they reduced the deficit with a brace of penalties from Mieres.
However, Homer continued his fine form with the boot with another from the tee, but the visitors' stand-off kicked them to within losing bonus-point territory.
Irish responded, though, as England full-back Delon Armitage fed Hape to score.
In a see-saw encounter, Exeter came back when Arscott touched down. Mieres added the extras but Irish still led 26-19. Homer and Mieres traded late penalties as the hosts held on.
For London Irish:
Tries: Ansbro, Hape
Cons: Homer 2
Pens: Homer 5
Pens: Mieres 5
London Irish: 15 Delon Armitage, 14 Topsy Ojo, 13 Joe Ansbro, 12 Shontayne Hape, 11 Tom Homer, 10 Steven Shingler, 9 Darren Allinson, 8 Richard Thorpe, 7 Jamie Gibson, 6 Declan Danaher, 5 Matt Garvey, 4 Bryn Evans, 3 Paulica Ion, 2 David Paice, 1 Clarke Dermody (c).
Replacements: 16 James Buckland, 17 Alex Corbisiero, 18 Leo Halavatau, 19 Bob Casey, 20 Alex Gray, 21 Adam Thompstone, 22 Adrian Jarvis, 23 Paul Hodgson.
Exeter: 15 Luke Arscott, 14 Gonzalo Camacho, 13 Nic Sestaret, 12 Phil Dollman, 11 Matt Jess, 10 Ignacio Mieres, 9 Haydn Thomas, 8 James Phillips, 7 James Scaysbrook, 6 Richard Baxter, 5 Chris Bentley, 4 Tom Hayes (c), 3 Craig Mitchell, 2 Simon Alcott, 1 Hoani Tui.
Replacements: 16 Neil Clark, 17 Brett Sturgess, 18 John Andress, 19 Aly Muldowney, 20 Tom Johnson, 21 Kevin Barrett, 22 Gareth Steenson, 23 Jason Shoemark.
Referee: Dean Richards