A 23-year-old man was hit by a car before being struck with a hammer in Dalton.
Detectives in Kirklees are appealing for information following the serious assault in the early hours of Monday.
The victim was walking along Cow Heys when a grey Volkswagen Golf went on to the footpath and hit him.
The driver and another man then got out and struck their victim with a hammer before driving away.
Det Insp Ian Thornes from Kirklees CID said: “Our enquiries are ongoing into this incident and we would appeal for anyone who witnessed the assault or has any information to please get in touch with police.”
The incident, which happened between 12.15am and 12.45am, was one of two on the same road that night.
An 18-year-old man was robbed at knifepoint by a man in his 20s around the same time.
Anyone with information about the assault should contact Pc Bonnie Bore at Kirklees CID by calling 101 and quoting crime reference 13170218315.
Information can also be passed anonymously to independent charity Crimestoppers on 0800 555 111.