A man riding a Muni bus on Geary Boulevard successfully fought an aspiring mugger Sunday, chasing the thief down and reclaiming his property.

According to the San Francisco Police Department, the 23-year-old victim was riding a Muni bus near Geary Boulevard and Baker Street — likely a 38, given the location — at 7 p.m. Sunday.

Police say that a man aged between 16-20 approached the victim and attempted to snatch his backpack. "A struggle ensued," police say, with the thief emerging triumphant.

Stolen backpack in hand, the robber then "exited the bus," the victim hot on his heels. Once the victim "caught up to [the suspect], another struggle ensued," police say, until the victim recovered his property.

Chagrined, the failed thief fled in an "unknown direction," according to the SFPD.

The victim received minor injuries in the altercation, police say, and was transported to San Francisco General Hospital. The suspect remains at large, and no arrests have been made in this case.