London Wasps ended Harlequins' ten match unbeaten run in all competitions with a dramatic 16-17 victory at the Stoop.
The result has pushed next week's opponents Leicester Tigers to the summit of the Aviva Premiership and inflicted Harlequins to their first home defeat since the final weekend of September of 2012.
The haunts of the London Double Header came flooding back in the early stages of this round 14 clash as both wingers, Christian Wade and Tom Varndell, crossed within the opening 15 minutes.
Harlequins were able to claw back to within one point at half time thanks to a try from Matt Hopper and eight points from Nick Evans' boot. In the second half, the quartered men rarely looked like taking the lead and with Evans converting only one penalty in three attempts, Robinson's three points on the hour marked proved to be enough for the victory.
Despite an early penalty miss from Robinson, the visitors raced into the lead with an interception from Varndell after eight minutes. With Harlequins in possession, Joe Gray acted as a scrum-half and his pass to Evans was low, which made it hard to gather.
Varndell continued to charge forward as Evans threw a wide miss pass which found the arms of the Wasps winger to run in untouched. Robinson added the extras and after Evans missed a penalty on ten minutes, Wade added a second blow with his try.
This time Wasps were in possession inside the Harlequins half and the ball was spun wide by the backline. The ball quickly passed between Elliot Daly, Chris Bell and eventually found Wade.
Charging down the left wing he crossed the line and scored. With a slight delay due to a TMO decision, the score was confirmed.
Harlequins responded well putting numerous phases together and gained valuable field position following two penalties. On the third penalty, Evans was within range and put Harlequins on the score board for the first time.
London Wasps continued to their ill-discipline following the restart and after two high tackles, Bell was shown yellow.
With a one man advantage, Harlequins responded with a superb try. James Johnston carved his way through in midfield and made light work of scrum-half Joe Simpson. The prop was finally brought down and after two phases of play, the ball was shipped to Hopper on the left wing. The centre grubber kicked down the wing and gathered possession to dive over the line.
Evans conversion reduced the gap to within four points and after adding another penalty on four minutes, the deficit was reduced to a point.
In the second half, Harlequins started strongly thanks to strong runs from Evans, Nick Easter and Ross Chisholm.
Maurie Fa'asavalu and Jordan Turner-Hall entered the fray and made an immediate impact. From a lineout on halfway the pair stormed up field and when Wasps conceded a penalty, play was on the five metre line. Despite this field position, Wasps turned over in the resulting phases and cleared.
Robinson added his final penalty just before the our mark when Easter infringed at the breakdown. Evans had three attempts on goal in the final 16 minutes of the match to reduce the four point deficit. Converting only one, this gave Wasps a one point cushion to secure the victory.