Police were called to reports of an assault at the junctions of Victoria Road and St. James Road just after 8.30am.
One man in his 50s has been arrested on suspicion of GBH.
A spokesperson from the Met Police says:
“Officers attended the scene alongside the London Ambulance Service and London’s Air Ambulance and located a man in his 50s with injuries. He was taken hospital where he is receiving treatment for potentially life-threatening injuries.
“A man in his 50s has since been arrested on suspicion of grievous bodily harm and possession of an offensive weapon. He remains in police custody.
“Anyone with information is asked to contact police on 101, quoting CAD 1584/28APR or Crimestoppers, anonymously, on 0800 555 111.”
A London Ambulance Service spokesperson said:
“We were called at 8.40am today to reports of person injured on Victoria Road, Surbiton.
“We sent resources to the scene including an ambulance crew, an incident response officer and a paramedic in a fast response car. We also dispatched London’s Air Ambulance.
“We treated a patient for a head injury and took them to a major trauma centre by road.”
