This win lifts United level on points with leaders Manchester City, albeit having played two games more than their bitter rivals. As for Southampton, they are without a point in four Premier League matches and stay in 12th after this historically bad result.
Manchester United put nine goals past Southampton in a record-equalling Premier League victory. Jankewitz was sent off for the visiting side a little over a minute into his debut and United took full advantage through goals from Wan-Bissaka, Rashford, Cavani and a Bednarek own goal before half-time.
Adams had a goal ruled out and United then added to their tally, with Martial netting twice either side of McTominay's drive and Fernandes converting a penalty that saw Bednarek red carded. James rounded off the scoring in added time.