Two men have been arrested on suspicion of GBH after a woman was found in the street with critical injuries in Wandsworth.
Police are appealing for witnesses and those with information to come forward.
Officers were called by the London Ambulance Service at 21:25hrs on Tuesday, 8 January to reports of a woman found unresponsive in the street on Fawcett Close, SW11.
The 41-year-old woman was taken to a south London hospital where she remains in a critical but stable condition.
Her next of kin have been informed.
The woman had suffered serious head injuries and is believed to have been the victim of an assault.
A crime scene is in place.
Two men aged 55 and 53 have been arrested on suspicion of grievous bodily harm.
They are currently detained at a west London police station.
Any witnesses or anyone with any information is asked to call police on 101 or contact via Twitter @MetCC. Quote CAD 7089/JAN
To give information anonymously contact Crimestoppers on 0800 555 111 or online at crimestoppers-uk.org.