A man has been found lying in the street with "life-threatening" injuries.
The victim was discovered seriously hurt in Cheltenham Road, Southend, Essex, just after 01:00 BST.
He was taken to Royal London Hospital where he remains in a serious condition, Essex Police said.
A woman, 32, has been arrested on suspicion of causing grievous bodily harm and remains in custody. Witnesses are urged to contact the force.