Just after 7:30 p.m., police responded to the stabbing in the 900 block of First Street where 23-year-old Joseph Tomada, of Benicia, had been stabbed numerously, police said.
James Samuel Bilbrey, 28, is the suspected stabber who was also at the scene suffering from assault wounds, possibly from another party, police said.
Both men were transported to John Muir Medical Center in Walnut Creek.
Bilbrey, of Richmond, is being charged with assault with a deadly weapon.
Police did not establish a motive but are still interviewing witnesses.