New signing Matthijs de Ligt grabbed his first goal for Manchester United while Marcus Rashford scored for the first time since March in a 3-0 Premier League victory at Southampton on Saturday after a shaky start to the season.
Alejandro Garnacho added a late goal for Erik ten Hag's side who started the day 14th in the standings after back-to-back losses.
They now have six points from four matches while newly promoted Southampton remain without a point.
Southampton dominated early on but squandered a chance to take the lead in the 34th minute after United goalkeeper Andre Onana saved Cameron Archer's poor penalty, sparking an immediate shift in momentum at St Mary's Stadium.