Three males launched an "unprovoked assault" on a lone man in Batley.
Police are appealing for information following the attack with what was thought to be a baseball bat yesterday at around 3.45pm on Oxford Street.
Officers said the 27-year-old victim was walking down Purwell Lane on to Oxford Street when a dark vehicle pulled up.
Three males got out of the car and assaulted him, police said.
The victim managed to get away from the offenders, who officers said were described as three Asian males, before they fled the scene.
Detective Constable Simon Thomas, of Huddersfield CID, said: “This was a frightening and unprovoked assault on a lone male.
“I would urge anyone who has any information about this incident or witnessed anything in the area to contact the police to assist with our investigation.”
Anyone with any information is asked to contact the police via 101, quoting crime reference number 13180002369.
Information can also be passed on to Crimestoppers anonymously on 0800 555 111.