Officers responded to a report of an assault outside the coffee shop at 1200 El Camino Real at 11:35 a.m., according to Belmont police.
Arriving officers found a 33-year-old man who had been struck in the head during a fight with another man.
The victim was taken to a hospital with injuries that were not expected to be life-threatening.
The suspect fled the scene in a 1990s Acura sedan, according to police.
A preliminary investigation revealed that the two men were acquainted and that Tuesday's assault likely stemmed from an ongoing dispute.
The suspect was described as a Hispanic male with a stocky build around 5 feet 10 inches tall.
Anyone with information on the case should contact Belmont police at (650) 595-7400.