A man was rushed to hospital with serious injuries after he fell from a balcony of a block of flats in Croydon.
Emergency services raced to the scene of the incident, which happened at Cromwell House in Roman Way, at about 12.30am on Friday.
A 43-year-old man was found injured at the scene and taken to hospital by paramedics.
He was initially fighting for life but his condition is now stable, police said.
Officers arrested a 45-year-old woman at the scene on suspicion of GBH.
She was taken to a south London police station and has since been released from custody.
Anyone who witnessed the incident or has any information is asked to contact police at Croydon on 101 or via Twitter @MetCC
Alternatively you can contact Crimestoppers anonymously on 0800 555 111.