Two officers responding to an unrelated incident heard shots fired around 7:35 a.m., Vallejo police Lt. Kenny Park said.
The officers were about a quarter-mile from Grant and Magazine streets, where 911 calls began coming in about a shooting, Park said.
They responded to that intersection and found a 38-year-old man from Vallejo suffering from gunshot wounds, according to Park.
He was critically wounded and was transported to the hospital, Park said.
When police responded to the shooting, they saw a small black Nissan speeding away. An officer chased the car, which accelerated to 90 mph as it traveled south on Fifth Street.
The driver, a black man in his 30s, sped through downtown and police eventually lost him, Park said.