Police say they do not know why the 31-year-old was in the area or why he was targeted.
The violent attack happened in Spiershall Terrace, Yoker, Glasgow, at about 2am.
The victim was taken to Western Infirmary where staff said his condition is serious.
Detective Inspector Ian Hylands, of Drumchapel CID, said: "At this time we do not know why the man, who is not local to the area, was in Yoker or why he was targeted by youths and subjected to such a violent attack.
"As well as carrying out local enquiries, we are checking CCTV in the area to try to identify those involved but would also appeal to anyone who saw or heard anything suspicious to come forward.
"Spiershall Terrace is a residential area and I am sure that people would have heard this disturbance - the noise would have been unusual for that time of night."
The attackers also vandalised the black Vauxhall Corsa, police said.