There was another twist in this strangest of matches when Wawrinka fired a forehand long in the following game to hand the break straight back, but a magnificent drop shot in game five helped the Swiss regain the advantage and this time he held on.
Five minutes later Floch, who had a magnificent first half, played a clever kick in behind Sale's defence and Nalaga did well to pick up and score the visitors' second try.
It was a magnificent first-half performance that set Quins on their way to a fourth win from their opening five matches, outstanding hooker Andy Ellis combining magnificently with half-backs Luke Gale and Chad Randall.