Crystal Palace pulled off a stunning extra-time victory at Old Trafford to reach the Carling Cup semi-finals and send Manchester United crashing out.

After a dull first half, Palace substitute Darren Ambrose thundered a 35-yard drive into the top corner.

United were on level terms four minutes later when Federico Macheda won and scored a penalty.

Glenn Murray headed in from a free-kick to put Palace ahead and they weathered a late storm to reach the last four.

United will point to the fact that Murray was marginally offside when the free-kick was taken, but the win was little more than the Championship club deserved after they refused to be overawed by their illustrious opponents.

Indeed, despite making 10 changes to the side that drew with Newcastle on Saturday, United boss Sir Alex Ferguson still picked eight full internationals and will have been shocked to see how badly his players coped with Palace's energy and purpose.

The south Londoners made a mockery of their dismal recent league form - they had not scored in their previous five games - by tearing into United from the first whistle, with their exciting 19-year-old Wilfried Zaha leading the charge.

The Ivory Coast-born winger had an appeal for a penalty turned down when he raced in behind the United defence and tumbled under a challenge from Fabio.

Replays suggested a foul should have been given, but that the contact between the players was outside the penalty area.

Clearly unsettled by Palace's electric start, United took time to settle into a passing rhythm and it took a mazy run from Antonio Valencia to fashion their first opening.

The Ecuadorian wideman teed up Dimitar Berbatov, but the striker - soon to be hauled off at half-time -screwed his shot wide.

United stayed on the back foot for most of the remainder of the half, with Palace dominating possession and territory.

Zaha continued to represent Palace's biggest threat, turning Jonny Evans to work himself some space, but driving his shot