A straphanger took out his wallet when a panhandler asked him for a dollar in a Manhattan subway station Wednesday — only to be punched in the face and have the billfold stolen, cops said.

The 37-year-old victim was near the turnstile at the 42 Street-Bryant Park subway station at around 11:30 a.m. when the panhandler asked for the money, cops said.

The man, who was believed to be homeless, then decked him, took the wallet and fled on a southbound D train, cops said.

“The pandhandler asked for a dollar,” a police spokesperson said. “He was punched in the face.”

The victim was taken to Bellevue Hospital for treatment, cops said. There were no arrests.