A man who plopped down in the middle of Park Avenue was seriously hurt after getting hit by a bus, police said.

The man, 30, may have been drunk when he chose at 5 am to lie down in the the right lane of the busy avenue near East 22nd Street, said cops.

A northbound MTA bus struck the man and kept going, said police, who noted the driver may not have realized the bus hit anyone.

The man, who was not identified, was in serious condition with head trauma at Bellevue Hospital,