A 19-year-old was taken to hospital with a head injuring after he was injured at an 18th birthday party this weekend.
The man, who is from the local area, was hurt in the car park of Wyberton Sports and Social Club shortly after 9pm on Saturday.
He has since been released from hospital.
A 24-year-old Boston man was arrested on suspicion of committing grievous bodily harm, and has now been granted police bail until April 1.
Anyone with information contact DC Sue-Ellen Wilson on 101, quoting incident number 428.