Joe Marler goaded James Haskell into a yellow card as Harlequins squeezed past Wasps in a 24-21 victory at the Ricoh Arena.
Quins inflicted Wasps’ first Aviva Premiership loss in Coventry since a 26-16 defeat to Saracens in December 2015 in a bad-tempered affair.
Two late penalties for teenage fly-half Marcus Smith edged the visitors home, Wasps paying the price for yellow cards to both Haskell and Danny Cipriani.
British and Irish Lions and England team-mates Marler and Haskell clashed in an unsavoury first-half incident, that saw Wasps flanker Haskell sin-binned.
Haskell lost his cool and throttled Marler off the ball – but insisted that was because the Quins prop choked him and squirted him in the face with water.
An irate Haskell called on referee Andrew Jackson to review the incident, claiming of Marler “he choked me with my scrum cap” and also “he squirted water in my face”.
Christian Wade and Tom Cruse struck tries for Wasps, but Marland Yarde and Charlie Walker responded for Quins.
But it was 18-year-old playmaker Smith who eventually booted the winning points as Wasps surrendered their 20-match Premiership winning streak at the Ricoh Arena.
Marler avoided punishment for clashing with Haskell but his latest controversy adds to his catalogue of previous issues.
The 27-year-old sought the help of sports psychologists after back-to-back bans for calling Wales prop Samson Lee “gypsy boy” and then kicking Grenoble’s Arnaud Heguy in the head in 2016.
Marler pulled out of England’s tour to Australia that summer, and has since cleaned up his act. But his latest antics could serve as a reminder of the thin line separating combative from careless.
Haskell certainly took exception to Marler appearing to tighten the strap of his scrum cap around his throat, and the water bottle incident caused the Wasps stalwart to loose his cool completely.
Smith and Danny Cipriani traded penalties in a frenetic opening, before Cruse bungled a clear try chance.
Wasps drew first try blood however, Daly, Marcus Watson, Le Roux and Wade all stacking the right wing to puncture Quins’ defence.
After some smart interplay it was Le Roux who sent Wade scuttling home for his 85th try in 135 Wasps appearances.
Haskell and Marler’s ugly tussle then truncated the half, and Wasps paid a quick price for losing their flank forward to…