A man needed 13 stitches after being slashed with a knife in Blackpool, police said.
Detectives are appealing for information after the 29-year-old victim became involved in a street fight with his attacker.
The incident took place on Lytham Road, close to the junction with Alexandra Road, at around 12.45pm on Sunday.
Police said the victim was approached by a man as he walked along the street and the pair reportedly began to fight.
The offender then pulled out a folding knife and ‘slashed’ the victim’s calf, police said.
The 29-year-old was taken to hospital for treatment.
Det Con Katie Brew, of Blackpool CID, said: “We are appealing to anyone who was in the vicinity at the time and witnessed the incident to contact us.”
A 22-year-old man from Blackpool was arrested on suspicion of wounding and has been released on bail pending further inquiries, the force said.
Anyone with information is asked contact Lancashire Police by calling 101 and quoting log 689 of May 14.
Alternatively, call Crimestoppers anonymously on 0800 555 111.