The altercation several blocks from the stadium Wednesday night was the second violent confrontation between the teams' fans in the past several years to end in death or serious injury. A Northern California paramedic and Giants fan suffered a traumatic brain injury after two men dressed in Dodgers gear attacked him following the teams' March 31, 2011, game in Los Angeles.
In Wednesday's attack, Jonathan Denver, 24, was in Dodgers gear and with his father and brother, San Francisco Police Chief Greg Suhr said. They got into a spat about the Giants-Dodgers rivalry around 11:30 p.m. with another group of people leaving a nightclub, one of whom was wearing a Giants hat, Suhr said.
The fight initially ended with no one seriously hurt, but it picked up again a few minutes later, Suhr said. He said it wasn't clear who started the second fight, but it ended with Denver's stabbing.
"Obviously, this is one of the most storied rivalries in baseball. That said, and I'm a big Giants fan, there is no place at these games for violence," Suhr said. "Nobody's life should be at stake whether they are at the game, leaving the game, whether it's six blocks away and an hour and a half after the game."
Denver attended the game with his relatives but left in the eighth inning of what turned out to be a 6-4 Giants victory. His attackers did not attend the game, Suhr said.
Two suspects were arrested shortly after the stabbing, but two others remained at large Thursday, Suhr said. He did not release their identities.
Police have not recovered the weapon used in the attack, which was witnessed by others, Suhr said.
The Giants and Dodgers are longtime division rivals, and passions tend to run high when the teams play. The Giants won the World Series last year but are set to miss the playoffs this year. The Dodgers, on the other hand, won the division.
Denver was born in Los Angeles County but was living in Fort Bragg in Northern California, a city about 170 miles north of San Francisco, according to public records. He and his brother came to San Francisco to attend the game with their father, a big Dodgers fan who lives in Southern California, said Cas Smith, the owner of North Coast Plumbing in Fort Bragg, where Denver worked.
"He was a hardworking kid," Smith told San Jose, Calif.-based KNTV.
The Giants said in a statement that they would observe a moment of silence for Denver at Thursday's game and increase security around the ballpark.
"While details are still emerging, we want to be clear that there is absolutely no place in our community for this type of senseless violence," the team said in a statement.
Police, too, said they planned to have more officers on the streets, although they said the police presence is already higher during Giants-Dodgers games.
Violence has marred previous contests between the teams. In 2003, Giants fan Marc Antenorcruz, 25, was fatally shot by a group of Dodgers fans after a drunken argument at Dodger Stadium.
Bryan Stow, the paramedic and Giants fan, was beaten in a parking lot after the Dodgers' 2011 home opener and spent two years in hospitals and rehabilitation centers.
Two Dodgers fans are awaiting trial on charges in the beating, which sparked outrage and brought stadium security changes around the state and country.
The Giants will donate $10 from each ticket sold in certain sections of AT&T Park at Tuesday, Thursday and Sunday's games to a fund setup for Stow, team spokeswoman Staci Slaughter said.
Suhr, meanwhile, urged fans to be mindful of their behavior.
"Please, be respectful of everybody rooting for whoever they want to root for," he said.
Contributing to this report were Associated Press writers Lisa Leff and Jason Dearen in San Francisco, and researcher Rhonda Shafner in New York.