The stabbing was reported at about 2:10 p.m. Wednesday in the 800 block of O'Farrell Street.
The two men were arguing when one pulled out a knife and attacked the other, police said.
The victim, a 54-year-old man, was able to wrest the knife away from the suspect and disable his wheelchair. Police responded and arrested the suspect, a 53-year-old man.
The victim suffered cuts to his ear and hand but refused transport to a hospital, police said.