Jonathan Spector grabbed a first-half brace to stun his former side with the only goals of his entire career in English football as United were punished for some alarmingly sloppy defending.
Carlton Cole grabbed a third in the 56th minute for the buoyant Hammers, then added his second just after the hour mark to send Avram Grant's side through to their first League Cup semi-final for 21 years with the Premier League table turned on its head. The harrowing defeat also ended United's longest unbeaten run in 11 years.
