A man is in a serious condition after a crash on an Auckland motorway early this morning.

Emergency services were called to the southbound motorway between State Highway 1 and State Highway 20 in Manukau at 2.30 this morning.

A northern fire communications spokesman said it was a single car crash and no one was trapped.

Northern ambulance communications shift manager Amanda Rochester said the man was transported to Middlemore Hospital with serious injuries.