Despite a sluggish first-half performance, when united fell behind early on Mbaye Diagne header which puts West Brom into a shocking lead after just 83 seconds.
Bruno Fernandes hauls Man Utd level with a fantastic screamer before the end of first half.
Man Utd have a penalty overturned by VAR in the second half but are back into second place on goal difference just behind Man City.
West Brom could also have snatched a late winner, but missed two glorious chances. United are now 19 games unbeaten away run in the Premier League.