Melbourne car theft attack, man critical

A man is in a critical condition after he was beaten unconscious and had his car stolen in Melbourne's east.

The 32-year-old went to get into his car at Box Hill South about 6pm on Saturday when he was attacked by at least two men and knocked out, police say.

He is still in a critical condition, a Royal Melbourne Hospital spokeswoman said on Sunday.

Witnesses say one of the offenders fled the scene in a second car.