14-Man Wasps sting Harlequins
Kyle Eastmond was red-carded in the first half following tries from Juan de Jongh and Young, and Harlequins surged ahead through efforts for Tim Visser and Aaron Morris.
But Wasps had a sting in the tail and attacked the hosts in the second half.
Willie le Roux, Young, Tom Cruse and Josh Bassett all added tries as the away side moved up to third in the table.
Wasps, sensing an opportunity to close the gap on table-toppers Exeter Chiefs, flew out of the blocks and took the lead within minutes of the kick-off.
De Jongh got the first try of the game after scrumhalf Dan Robson burst through and kicked ahead, allowing the South African to touch down after the ball fell kindly in the end zone.
A Marcus Smith penalty reduced the gap but Wasps grabbed a second shortly after when the impressive Youngs stretched to dot down in the corner.
However, any Wasps joy was short-lived when referee Wayne Barnes dismissed Eastmond for a high tackle on Smith.
And Harlequins made them pay as Visser and Morris crossed either side of the break to put them ahead.
The hosts were the major favourites from there but Wasps produced a superb second-half come back with Le Roux, Youngs, Cruse and Bassett all scoring.
Charlie Matthews also scored for Harlequins but they were unable to get back into the contest and were left to bask in Wasps’ brilliance.
Tries: Visser, Morris, Matthews
Cons: Smith 2
Tries: De Jongh, Young 2, Le Roux, Cruse, Bassett
Cons: Cipriani 4
Pens: Cipriani 2
Yellow Card: Archie White (Harlequins, 62)
Red Card: Kyle Eastmond (Wasps, 16)
Harlequins: 15 Ross Chisholm, 14 Alofa Alofa, 13 Joe Marchant, 12 Jamie Roberts, 11 Tim Visser, 10 Marcus Smith, 9 Dave Lewis, 8 Mat Luamanu, 7 Luke Wallace, 6 James Chisholm, 5 Charlie Matthews, 4 Ben Glynn, 3 Kyle Sinckler, 2 Dave Ward (captain), 1 Lewis Boyce
Replacements: 16 Joe Gray, 17 Mark Lambert, 18 Will Collier, 19 Stan South, 20 Archie White, 21 Jono Kitto, 22 Ian Prior, 23 Aaron Morris
Wasps: 15 Willie le Roux, 14 Christian Wade, 13 Juan de Jongh, 12 Kyle Eastmond, 11 Josh Bassett, 10 Danny Cipriani, 9 Dan Robson, 8 Guy Thompson, 7 Thomas Young, 6 Jack Willis, 5 Kearnan Myall, 4 James Gaskell (captain), 3 Jake Cooper-Woolley, 2 Tom Cruse, 1 Simon McIntyre
Replacements: 16 Ashley Johnson, 17 Matt Mullan, 18 Marty Moore, 19 Marcus Garratt, 20 Nathan Hughes, 21 Joe Simpson, 22 Jimmy Gopperth, 23 Gaby Lovobalavu
Referee: Wayne Barnes
Assistant referees: Hamish Smales, Jonathan Healy
TMO: Stuart Terheege