United have now lost three of their opening six league games for the first time since 1989-90.
Manchester United 1
West Brom 2
David De Gea - Saved from Berahino with his feet and Amalfitano but outwitted for West Brom's goals.
Phil Jones - Troubled by Sessegnon's pace and booked for a foul on the Benin international.
Jonny Evans - Wasn't much better than Ferdinand after the restart.
Rio Ferdinand - Nutmegged by Amalfitano for West Brom's opening goal and looked shaky.
Alexander Buttner - Booked for a late challenge.
Nani - Faded after a strong first half but almost created the equaliser for Fellaini.
Anderson - Disappointing display marked by blasting a volley way into the stands.
Michael Carrick - Struggled to get a hold in the centre of the park.
Shinji Kagawa - Replaced by Januzaj at half-time.
Wayne Rooney - Produced the equaliser when his free-kick from the left eluded everyone.
Javier Hernandez - Was replaced by Robin Van Persie on 58 minutes.
Robin van Persie - A couple of sights at goal late on but unable to force an equaliser.
Marouane Fellaini - Thought he had drawn United level but offside.
Adnan Januzaj - Showed glimpses of his skill and pace.
David De Gea - Not tested in the first-half.
Phil Jones - Awkward on the turn, does not look a natural full back.
Jonny Evans - Solid performance from the maturing defender.
Rio Ferdinand - Some questionable decisions, worried by Anichebe's pace.
Alexander Buttner - Has his hands full with Stephane Sessegnon and lost the Benin international at the back post who missed a great chance.
Nani - Looking United's most dangerous weapon, great delivery.
Anderson - Hit the crossbar with a header which was wrongly flagged for offside but not a real box-to-box dynamo.
Michael Carrick - Steady but even the normally reliable Carrick has been guilty of misplacing simple passes.
Shinji Kagawa - Completed 100% of this passes in the opening 15 minutes and became more of a threat as the half continued.
Wayne Rooney - Dropping very deep and looking to create from midfield. Seen plenty of the ball.
Javier Hernandez - Some neat link-up play but no sights at goal.