Two housemates are in hospital, one with a 20-centimetre wound to his abdomen, after balaclava-clad thieves stormed into their home and stole a brand new Ford Mustang, cash and an ANZAC anniversary ring.

Three men wearing balaclavas, and armed with what's believed to be a screwdriver or chisel and pipe, knocked on the door of the men's Reservoir home on Excelsior Street about 1am on Wednesday before forcing their way inside.

A man has been stabbed in the abdomen and another bashed during a violent aggravated burglary in Reservoir on Excelsior Street. Credit:3AW

Police say the terrifying home invasion appears to be a random attack.

"At this point we believe they've knocked on the door, the door was open and they've forced their way in," Detective Acting Senior Sergeant Phil Crawford told The Age.