Lincolnshire Police have arrested a woman on suspicion of assaulting another reveller with a glass on Sunday.
The incident happened on February 20 at around 2.30 in popular city bar Dogma on the High Street.
A man, aged 31, was struck in the face with a glass. He has been treated for a 7cm cut.
Officers arrested a 21-year-old woman shortly after. She was questioned and released on police bail.
Further enquires will be made on March 17.