London  - Manchester United overcame a 1-0 first-leg deficit on Tuesday, beating Derby County 4-2 in the second leg to secure their place in the Carling Cup final by a 4-3 aggregate.

Kris Commons had given Derby a surprise first-leg victory, but they were blown away before half-time at Old Trafford, conceding three goals in a 20-minute spell.

Nani got the first with a spectacular swerving drive, although television replays suggested goalkeeper Roy Carroll might have done rather better.

John O'Shea, played onside by Gary Teale, rolled in his first of the season to make it 2-0, and Carlos Tevez headed a third from a Rafael cross.

Derby steadied in the second half, and pulled one back with an 80th minute Giles Barnes penalty, after Jonny Evans had tripped Paul Green.

Cristiano Ronaldo converted an 88th-minute penalty after a foul by Carroll on Tevez seemingly to make the game secure.

But Derby still weren't finished, Barnes driving in a low free-kick in injury-time.

Tottenham Hotspur take a 4-1 first-leg lead to Burnley in Wednesday's second semi-final. dpa