Van Gisbergen, kicking instead of Cipriani, drew Wasps back into it with two penalties of his own and Varndell struck again just before the interval after Wasps stole line-out ball on the Quins 22.
And there was no let-up after the interval, the Warriors' line being breached again three more times before the home side ran in three late tries through George Carmont, skipper Sean O'Loughlin and Stefan Marsh.