Full back Mike Brown's 80th minute score made it a third bonus-point triumph in succession for Quins as director of rugby Conor O'Shea's men secured a 37-14 win over winless Sale Sharks at the
Stoop on Saturday.
Ugo Monye and Jordan Turner-Hall tries put Harlequins in charge with a 14-8 lead at the break, before three second-half Nick Evans penalties extended their advantage to 23-11.
George Robson scored his third try of the season in the final quarter to give QUins renewed hope of securing the try-scoring bonus point, before Brown put the seal on the win late in the day.
O'Shea's men are two points clear at the top of the table ahead of this Saturday's trip to Leicester Tigers.