A gang – armed with a crow bar and a golf club – assaulted a cyclist in Dewsbury on Tuesday night.
The attack happened at around 7.15pm when a man in his 40s was cycling along Park Road in Earlsheaton.
The cyclist was approached by the four men and struck with the weapons before being left lying injured in the road.
A passer-by stopped to phone police and the ambulance service.
The victim was shaken but conscious at the scene. He was taken to hospital and suffered minor injuries.
An eyewitness said: “I saw two young men sat opposite the Park Hotel with golf clubs in their hands. We were all laughing and joking about them playing golf in the park then they walked towards Dewsbury .
“Next thing they were battering a man on a bike with the golf clubs. They were hitting him that hard.”
A West Yorkshire Police spokeswoman said: “The victim received minor injuries and enquiries remain ongoing.”
Anyone with information should contact police on 101, quoting crime reference 13170174657.