The robbery was reported around 8:25 p.m. in the 100 block of Kiska Road.
When the 20-year-old victim answered a knock at his door, a group of suspects forced their way in and began punching him in the face and body, according to police.
The suspects went through the victim's pockets and stole his cellphone and cash. They also ransacked the house before fleeing, police said.
The victim was taken to San Francisco General Hospital to be treated for a cut to his eye and other injuries that are not considered life-threatening.
The suspects, described as four men in their 20s -- two of whom were wearing ski masks -- had not been found as of this morning.
Anyone with information about the case is encouraged to call the Police Department's anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411.
