|Harlequins (10) 22|
|Tries: Visser, Morris, Matthews Con: Smith 2 Pen: Smith|
|Wasps (15) 44|
|Tries: De Jongh, Young 2, Le Roux, Cruse, Bassett Con: Cipriani 4 Pen: Cipriani 2|
Wasps shrugged off Kyle Eastmond's red card after only 17 minutes to score six tries in a fine win at Harlequins.
Eastmond was dismissed for a swinging arm at Marcus Smith with Wasps ahead through Juan de Jongh and Thomas Young.
But even with 14 men, Wasps scored flowing tries when Young got his second and Willie le Roux scored, before Tom Cruse barged over and Josh Bassett touched down Danny Cipriani's grubber.
Aaron Morris, Tim Visser and Charlie Matthews replied for Harlequins.
The home side produced their most controlled period of the match as the clock ticked over the 80-minute mark but they failed to secure a try bonus point and now sit 10 points behind the play-off places.
Harlequins were level at 15-15 shortly after half-time as Morris gathered a swirling box kick on the left wing and found himself with a clear run to the line, but Wasps then took control to return to third in the Premiership.
Christian Wade made a clean break from his own half before Dan Robson and De Jongh set up Young for his second try.
Cipriani then broke from just outside his own 22, sent De Jongh into space and his delayed pass put Le Roux under the posts for the bonus-point try.
England number eight Nathan Hughes came off the bench for the final 24 minutes, his first appearance for four months, and helped drive Cruse over for Wasps' fifth try before Cipriani applied the coup de grace with a delicate grubber kick that gave Bassett the most simple of finishes.
Harlequins director of rugby John Kingston:
"We've let our supporters and our families down as there was a half-empty stadium with 20 minutes to go and I let the players know my feelings in the changing rooms.
"We should have gone into half-time well ahead but we blew at least three good chances.
"We were level with 30 minutes to go and well set against 14 men but we switched off for a five-minute period and they were pretty lethal."
Wasps director of rugby Dai Young:
"People have questioned our mentality in the past but we showed plenty of bottle and attitude.
"After Kyle's dismissal, the message went out to conserve energy in our half but to raise the tempo when we got in theirs.
"It was one of our best performances of the season but it could have been a lot closer as we took our opportunities and they missed a couple of theirs."
Harlequins: R Chisholm; Alofa, Marchant, Roberts, Visser; Smith, Lewis; Boyce, Ward (capt), Sinckler, Glynn, Matthews, J Chisholm, Wallace, Luamanu.
Replacements: Gray, Lambert, Collier, South, White, Kitto, Prior, Morris.
Sin-bin: White (63)
Wasps: Le Roux; Wade, De Jongh, Eastmond, Bassett; Cipriani, Robson; McIntyre, Cruse, Cooper-Woolley, Gaskell (capt), Myall, Willis, Young, Thompson.
Replacements: Garratt, Mullan, Moore, Hughes, Johnson, Simpson, Gopperth, Lovobalavu.
Sent off: Eastmond (17)
Referee: Wayne Barnes.