Scrum dominance sparked Northampton to a 39-13 bonus-point victory over Gloucester to extend their club-record unbeaten Aviva Premiership run to 13 games.
Saints climbed back to the top of the table with their five-try win, replacing Saracens who had led the standings courtesy of Friday's victory at Bath.
Ken Pisi, Calum Clark, Tom Stephenson, Alex Waller and Will Hooley scored for Northampton as they cut loose in the second half.
Henry Trinder's try and a conversion and two penalties for Freddie Burns had Gloucester level at 13-13, before Clark plundered the pivotal score just before the hour.
Sale took a significant step towards European qualification by defeating Wasps 21-17 at Adams Park.
The Sharks remain in sixth position in the Aviva Premiership table, but crucially they have extended their lead over Wasps - in seventh - by a further three points, which leaves them with a handy eight-point advantage over their nearest rivals.
The controversial moment of the game came in the 10th minute with the sin-binning of Joe Simpson. The Wasps scrum-half high tackled Nick Macleod who took no further part in the game.
The incident was reviewed and a yellow card was awarded but Simpson may have been fortunate not to pick up a red one.
Sale scored a decisive 10 points in Simpson's absence. Danny Cipriani kicking a penalty and a conversion to add to Dan Braid's try before Wasps rallied to score 17 unanswered points. Joe Carlisle kicked four penalties before Simpson raced away for his side's only try.
The final quarter saw the Sale pack dominate and they recovered from 17-10 down with an unconverted Jonny Leota try before Cipriani kicked over two penalties in the final 20 minutes.
Exeter Chiefs saw their run of five-straight defeats in the Aviva Premiership come to an end as they completed a season double over London Irish with an 18-0 victory.
The home side led 6-0 at the break through two Henry Slade penalties, while James O'Connor saw his one attempt at the post rebound back but the visitors were reduced to 14 men midway through the half with prop Leo Halavatau shown yellow.
The Chiefs added two tries in the second half with Phil Dollman's touchdown - converted by Slade - and an Ian Whitten effort, although their resolve was tested when they had Ben White yellow carded for a tip tackle on the hour mark.
Sam Smith, who has agreed to join bottom-of-the-table Worcester in the summer, sunk his future club as Harlequins came from 13-0 down to win 21-20 and narrowly deny the Warriors their first win of the season.
The 23-year-old winger scored a try and then created a second for debutant centre Harry Sloan as Quins, trailing until the 63rd minute, rallied to inflict a 16th successive defeat on Worcester.
Fly-half Ben Botica, stand-in for the injured Nick Evans, kicked Quins' other 11 points.
Worcester had opened up a 13-0 lead with a penalty from full-back Chris Pennell, a scintillating try from Samoan winger David Lemi and a conversion and penalty from fly-half Ryan Lamb, making his first start since his arrival from Leicester.
Pennell's late try and conversion earned them a losing bonus point.