A man has been found with serious head injuries lying in the middle of a road in Sydney’s inner west after allegedly being assaulted.

The 51-year-old, found on Punchbowl Road at Belfield, just before midnight on Monday, told police he was attacked and robbed after he pulled into a nearby industrial complex.

He says several vehicles were blocking the entrance, and when he got out of his car he was struck from behind and then punched in the face.