Casandra Buenrostro, 25, who arrived at the plaza at 5 a.m. so she could get pictures of Sandoval, did.
"He made me cry," Buenrostro said. "He's an inspiration."
Star reliever Sergio Romo, wearing a T-shirt that read, "I just look illegal," whipped the roaring crowd into a frenzy when he got out of his convertible and mingled.
"It's unbelievable! Unbelievable! Just great!" said fired-up right fielder Hunter Pence, who was acquired in a midseason deal and led pregame pep talks. At the rally, Pence persuaded his teammates to jump around the stage to demonstrate the ritual he called the "slow-clap."
"I loved it when they started acting goofy," said Janet Clark, 55. "That's exactly who the Giants are."
San Francisco police spokesman Michael Andraychak said 22 arrests were made, including 13 for public intoxication, but said the crowds generally were cooperative.
Some fans carried brooms as a reminder of the Giants' four-game sweep of the Detroit Tigers. Later, San Francisco Mayor Ed Lee handed Giants President Larry Baer a ceremonial metal "broom to the city" along with the customary key.
Alex Warlen and Kelly Simms, both 17, were among the hundreds of people who camped out overnight in the plaza to ensure they had prime viewing spots. Warlen is a pitcher and Simms a catcher for the softball team at San Francisco's Mercy High School. The team is co-champion of its division.
"Buster is the reason I'm a catcher," read a sign Simms carried, referring to the Giants' Buster Posey. The high school seniors said Mercy administrators gave students the day off, so they weren't cutting school.
"We would have skipped anyway," Simms said.