The robbery was reported at about 11:15 p.m. in the 300 block of 27th Street.
A 58-year-old man came home to find the other victim, a 69-year-old man, tied up and suffering from a cut wound. The 58-year-old man was then attacked with a hatchet by three male suspects in the home, according to police.
Both victims suffered deep lacerations and were taken to a hospital to be treated for their injuries, which are not considered life-threatening, police said.
The suspects fled and had not been found as of this morning. Anyone with information about the robbery is encouraged to call the Police Department's anonymous tip line at (415) 575-4444 or to send a tip by text message to TIP411.