Sale Sharks can seal the final Premiership play-off place with a win after Saracens stormed back to deny Bath victory.
Chris Robshaw's last game at The Stoop ended in defeat for Harlequins as Wasps enhanced their chances of finishing in the top four.
A 1,000-strong crowd were allowed to watch Gloucester's Premiership defeat to Harlequins on Monday.
Leicester Tigers were thrashed by Wasps while Sale Sharks held off Saracens in Wednesday's Premiership matches.
Just under 3,000 fans returned to see Harlequins lose to Bath, while Owen Farrell saw red for a high tackle as Saracens lost against Wasps.
Ollie Thorley scored four first-half tries in Gloucester's win against Leicester, while two Exeter hat-tricks helped to crush Worcester.
Worcester Warriors won their first game of 2020 on Wednesday, while Bath's strong second-half display led them to a third win a row.
Harlequins were unable to recover from a dominant first-half display by rivals Saracens at Allianz Park.
Jack Clifford is "absolutely gutted" to have to end his career at the age of 27 after failing to recover from a shoulder injury.
Marcus Smith caught the eye and mid-table Harlequins scored a narrow win over Sale Sharks as top-flight rugby union resumed in England.