A female cyclist is fighting for life after a hit-run in Chelsea. Credit:James Bird/Ten News Melbourne

A man has been charged and a cyclist is fighting for life after a hit-run in Melbourne's south-east.

A 50-year-old woman was riding her bike on the Nepean Highway near Chelsea Road, Chelsea, about 5.40am on Thursday when she was struck by a white ute.

She was rushed to The Alfred hospital where she remains in a critical condition with life-threatening injuries to her head and chest.

Later on Thursday, police arrested a 28-year-old Parkdale man in Broadmeadows within hours of the incident. The ute was found in Seaford about 8.15am.