The man was chased and seriously assaulted at about 11.15pm on Saturday on Tormore Street near Cardonald Railway Station, Police Scotland said.
He was taken by his two friends, who were not injured, to Southern General Hospital in Glasgow.
Detective Constable Kenneth Johnston, from Govan CID, said: "This appears to be an unprovoked attack on the man who was making his way home with his friends, and thankfully they had the presence of mind to take him to the nearby hospital.
"Extensive inquiries are continuing and I would appeal to anyone who was in the Berryknowes Road, Tormore Street area around 11pm on Saturday and saw a group of men to get in touch."
The group of six or seven attackers are described as white, Scottish and in their late teens to early 20s.