The boy was struck around 10:30 p.m. PST while walking away from the Giants game at AT&T Park.
9-year-old Ryan White of Philadelphia was walking just ahead of a family member in a crosswalk on Mission Street when a pickup truck coming off New Montgomery turned left and hit the boy. The pickup then hit several cars before getting on the freeway and fleeing the scene.
"The car came screeching out of the street. Hit one car, careened over into the second car and that was where my son was. And that car continued down the street. I understand he hit several other cars and drove away," said Ryan's father, Ken.
Several hours later, police in Hayward - a city located southeast of San Francisco - discovered a damaged white Toyota pickup truck that matched the description of the striking vehicle.
Officers gave the driver a preliminary alcohol screening and he was determined to be over the legal limit of .08 BAC.
San Francisco police traveled to Hayward to investigate. Witnesses they brought along identified the truck and driver as the same from the scene of the hit and run.
The driver was arrested and turned over to San Francisco police. The truck was impounded as evidence.
The suspect is identified as Andrew Vargas, 21, of Hayward. He is being charged with felony hit and run and well as driving under the influence. Bail is set at $65,000.
According to San Francisco police, Vargas has been placed in a psychiatric ward and is on suicide watch at this hour.
White remains hospitalized in critical condition having suffered head injuries, which have been described as non-life threatening injuries.
"It's been an up and down night and they are doing some more tests and we are awaiting the results of that. It will be a while before we know. So it's been difficult, as you can imagine," said Ken White.
Police say White was in San Francisco visiting family.