Harlequins resisted a second half comeback from Sale Sharks to claim a 48-41 win at The Stoop.
Tries from Mike Brown and George Lowe, both converted by Nick Evans, put the hosts ahead before a penalty from Nick Macleod and a Rob Miller try got Sale back in the match.
Evans then kicked a penalty for Quins, and tries from Ollie Kohn, Mark Lambert and a second for Brown stretched the lead.
Sale's Dwayne Peel scored on half-time, and Macleod's conversion made it 38-17 at the break.
Harlequins began the second half stronger, and Evans' converted try combined with Rory Clegg's penalty looked to have put them out of sight.
However, a second try for Miller and converted scores from Vadim Cobilas, Tom Brady and Joaquin Tuculet earned the Shark's a losing bonus point.