Free-flowing Northampton score nine tries as they abruptly end Sale's five-game unbeaten Premiership run.
Premiership Rugby wants "crucial" discussions with the RFU on the future competition structure of the professional club game in England.
Sale centre Mark Jennings will take a break from professional rugby for the foreseeable future, the club says.
Worcester Warriors beat Wasps to reach the Premiership Rugby Cup semi-finals while Newcastle also claim a last-four spot.
Audio & Video
Ugo Monye explains why England winger Marland Yarde is set to join Sale Sharks from Harlequins.
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