Harlequins picked up a valuable 24-3 victory over Sale at the Stoop on Saturday, a win that sees them leap-frog the Sharks in the standings.
Three Ben Botica penalties to Danny Cipriani's one saw Quins take a 9-3 lead into the interval before Luke Wallace's early second-half try extended their advantage.
Botica added a fourth three-pointer and Jack Clifford touched down to seal an important win.
The hosts went into the game decimated by a number of injuries and international call-ups while their opponents, who have started the season well, were close to full strength.
However, it was the London-based outfit that dominated the opening stages of the half, with their off-loading game to the fore.
But Sale resisted the barrage well and Botica's penalty was their only reward for the possession and territory they had enjoyed.
The Sharks gradually grew into the match, though, and Cipriani levelled proceedings after 25 minutes with a three-pointer of his own.
Quins then went back on the front foot and successive penalties from their centre gave them a 9-3 advantage at the interval.
Although the visitors started the second period well, after a Rob Miller break threatened the hosts' rearguard, an excellent piece of skill saw Conor O'Shea's men open up a comfortable gap when Nick Evans' cross-kick found Wallace who touched down.
Botica missed the conversion, but the New Zealander was soon on target again with a fourth penalty of the afternoon.
And Clifford sealed a crucial win after charging down Joe Ford's attempted clearance to run over unopposed.
Tries: Wallace, Clifford
Pen: Botica 4
Harlequins: 15 Tom Williams, 14 Ugo Monye, 13 Matt Hopper, 12 Ben Botica, 11 Sam Smith, 10 Nick Evans, 9 Karl Dickson, 8 Tom Guest, 7 Luke Wallace, 6 Joe Trayfoot, 5 George Robson, 4 Nick Easter (c), 3 Will Collier, 2 Dave Ward, 1 Mark Lambert.
Replacements: 16 Harry Allen, 17 Darryl Marfo, 18 Kyle Sinckler, 19 George Merrick, 20 Jack Clifford, 21 Danny Care, 22 Paul Sackey, 23 Charlie Walker.
Sale Sharks: 15 Rob Miller, 14 Tom Arscott, 13 Jonny Leota, 12 Sammy Tuitupou, 11 Mark Cueto, 10 Danny Cipriani, 9Dwayne Peel, 8 Mark Easter 7 David Seymour, 6 Dan Braid, 5 Andrei Ostrikov, 4 Jonathan Mills, 3 Henry Thomas, 2 Tommy Taylor, 1 Eifion Lewis Roberts.
Replacements: 16 Marc Jones, 17 Ross Harrison, 18 Vadim Cobilas, 19 Kirill Kulemin, 20 Tom Holmes, 21 Will Cliff, 22 Joe Ford, 23 Andy Forsyth.
Referee: Luke Pearce
Assistant referees: Ashley Rowden, Stuart Terheege
TMO: Graham Hughes