United squeak past zesty Wolfsburg
Midfielder Michael Carrick struck the winner 12 minutes from time after Ryan Giggs's deflected free kick had cancelled out a fine header from Bosnian striker Edin Dzeko which had handed the German champions a shock lead soon after halftime.
United, seeking to reach the final for the third season in a row, started slowly and striker Michael Owen, struggling with a groin injury, had to be replaced by Dimitar Berbatov after just 19 minutes.
United's threat was limited in the opening period and the closest they came to breaking the deadlock was a Carrick shot that was blocked by Wolfsburg goalkeeper Diego Benaglio.
Nine minutes after the restart, Dzeko rose above Patrice Evra to nod Makato Hasebe's cross past Tomasz Kuszczak and give Wolfsburg a shock lead in their first Champions League campaign.
But Giggs's free kick flew in off Chrstian Gentner to pull United level and the veteran midfielder then laid the ball off for Carrick to curl it into the top corner and secure United's eighth consecutive victory in all competitions.