Harlequins kept up their stunning away record in the Premiership this season as they swept Wasps aside for a third bonus-point triumph on their travels.
Quins have not won at home yet in three attempts, but scored six tries to earn their biggest win of the campaign.
Will Evans and Danny Care helped them to a 20-3 half-time lead bolstered by Alex Dombrandt and Louis Lynagh tries.
Zach Kibirige and Tom Willis replied before James Lang scored for Quins, followed by an added-time penalty try.
The game ended in the red zone just when it seemed the final action was done as Lang cashed in a dropped pass from Jimmy Gopperth to enjoy a 50-metre run to the line.
Marcus Smith landed the conversion, his seventh successful kick for an individual 17-point haul, but referee Luke Pearce was not done, allowing play to continue and bringing a sixth try for Quins, who also scored six in their first away win of the season at Gloucester.
Gopperth landed both his conversions, to add to Lima Sopoaga's first-half penalty - but it was a poor showing by a Wasps side badly missing their England players, Paolo Odogwu, Dan Robson, Jack Willis and Joe Launchbury.
Head coach Lee Blackett made nine changes to the side which beat Bath last time out - and the only consolation was winger Kibirige, last season's top scorer, going in for his first try of the season.
They are fifth in the table, and only above Harlequins by virtue of games won - four to three - as the London club have a superior points difference.
Wasps: Sopoaga; Kibirige, Fekitoa, Gopperth, Minozzi; Umaga, Porter; McIntyre, Cruse, Toomaga-Allen, Rowlands, Gaskell, Shields, Young (capt), T Willis.
Replacements: Taylor, Harris, Brookes, Cardall, Morris, Wolstenholme, Le Bourgeois, Miller.
Harlequins: Brown; Lynagh, Marchant, Esterhuizen, Morris; Smith, Care; Marler, Baldwin, Louw, Symons, Lewies (capt), White, Evans, Dombrandt.
Replacements: Elia, Els, Kerrod, Young, De Carpentier, Landajo, Lang, Green.
Referee: Luke Pearce.