Piutau shines as Wasps edge Chiefs in thriller
Two-time European champions Wasps were 11-24 behind early in the second half but staged a dramatic rally, with Piutau scoring two tries.
The second of those left Jimmy Gopperth with a touchline conversion to win the match with the last kick of the game and Piutau's fellow Kiwi made no mistake with the difficult kick.
Wasps will now face the winners of Saturday's second all-English quarterfinal between Premiership leaders Saracens and Northampton in the last four.
Gopperth kicked two early penalties to give home side Wasps a 6-0 lead in Coventry.
But Exeter hit back when former England No.8 Thomas Waldrom scored two tries in quick succession.
The first was a typical loose forward's score, with Waldrom driven over from close range just after the half-hour mark.
But the second saw Waldrom pick off a stray pass and charge in from 30 metres out, the back-row sliding in for his 19th try of the season in all competitions.
Gareth Steenson converted both scores and Exeter led 14-6 at half-time.
Wasps, however, responded with a try at the start of the second half when, at a rain-sodden Ricoh Arena, Charles Piutau raced on to a well-weighted grubber kick from Dan Robson.
Gopperth missed the difficult conversion but Exeter's lead had been cut to three points a 14-11.
Exeter's forwards were still proving a powerful force though and prop Harry Williams was driven over for the south-west side's third try in the 48th minute.
Steenson converted and former England lock Geoff Parling almost had another try but his effort was ruled out for a forward pass.
Steenson though nudged Exeter further in front with a penalty to make it 24-11.
Frank Halai started Wasps' late fightback with a 65th-minute try converted by Gopperth.
Man of the match. Thomas Waldrom was brilliant for the Exeter Chiefs and scored two tries. However, our award goes to All Black Charles Piutau who ripped the Chiefs' defence to pieces on a number of occasions and he scored two crucial tries – one of which got the win.
The scorers:
For Wasps:
Tries: C Piutau 2, Halai
Cons: Gopperth 2
Pens: Gopperth 2
For Exeter Chiefs:
Tries: Waldrom 2, Williams
Cons: Steenson 3
Pen: Steenson
Teams:
Wasps: 15 Charles Piutau, 14 Christian Wade, 13 Elliot Daly, 12 Siale Piutau, 11 Frank Halai, 10 Jimmy Gopperth, 9 Dan Robson, 8 Nathan Hughes, 7 George Smith, 6 James Haskell (captain), 5 Kearnan Myall, 4 Joe Launchbury, 3 Jake Cooper-Woolley, 2 Carlo Festuccia, 1 Matt Mullan.
Replacements: 16 Ashley Johnson, 17 Simon McIntyre, 18 Lorenzo Cittadini, 19 Bradley Davies, 20 Thomas Young, 21 Joe Simpson, 22 Ruaridh Jackson, 23 Rob Miller.
Exeter Chiefs: 15 Lachie Turner, 14 Jack Nowell, 13 Henry Slade, 12 Ian Whitten, 11 Olly Woodburn, 10 Gareth Steenson (captain), 9 Will Chudley, 8 Thomas Waldrom, 7 Julian Salvi, 6 Don Armand, 5 Geoff Parling, 4 Mitch Lees, 3 Moray Low, 2 Luke Cowan-Dickie, 1 Ben Moon.
Replacements: 16 Jack Yeandle, 17 Alec Hepburn, 18 Harry Williams, 19 Damian Welch, 20 Dave Ewers, 21 Dave Lewis, 22 Michele Campagnaro, 23 James Short.
Referee: Romain Poite (France)
Assistant referees: Peter Fitzgibbon (Ireland), Tual Trainini (France)
TMO: Simon McDowell (Ireland)
Agence France-Presse