Saracens won a fifth straight Premiership match, though they are still far behind Leicester Tigers, who were defeated by Exeter Chiefs.
Northampton Saints made it four wins from five to go top of the Premiership, while Exeter Chiefs thrashed Wasps.
Captain Joe Launchbury believes the future is bright for Wasps after signing a new deal.
Rob du Preez kicked 17 points while his brother Dan scored Sale Sharks' only try in a hard-fought 28-18 Premiership victory over Wasps.
A late Harry Williams try proved decisive as Exeter Chiefs came from 14 points behind to overcome Worcester Warriors.
Saracens were on the brink of a second defeat in three Premiership games but they battled back to defeat London Irish.
Northampton Saints and Gloucester followed up narrow away wins on the opening weekend by easing to home successes in the Premiership.
Wasps fell just short in their comeback bid as London Irish made a winning start in their return to the Premiership.
MMA promotion Bellator has signed former England rugby union star James Haskell, who is expected to make his debut in 2020.
Although their chances of reaching the play-offs were remote, Wasps still had hope until slumping in the second half at Bath on Sunday.
Exeter Chiefs and Saracens kept winning at the top on Saturday, while Leicester Tigers' Premiership status is not yet secured.
A bonus point and a piece of history made it the happiest of Sunday's for Wasps, who defeated Exeter Chiefs 26-19 at Sandy Park.
Wasps confirmed that England number nine Dan Robson needs treatment for deep vein thrombosis that will last three months.
Now a member of the Buffalo Bills, Christian Wade believes his decision to trade rugby union for the NFL has been vindicated.
Christian Wade will continue to pursue his NFL dream with the Buffalo Bills and conceded to being "lost for words".
Exeter Chiefs earned a home semi-final with four games to spare, while Saracens scored a late try to hurt Newcastle's survival hopes.