Marco Scutaro singled home the tiebreaking run in the 10th inning, and the San Francisco Giants beat the Detroit Tigers 4-3 on Sunday night to complete a four-game sweep and win their second World Series title in three years.

Matt Cain #18 and Jeremy Affeldt #41 of the San Francisco Giants celebrate their World Series win. (Doug Pensinger/Getty Images)

Ryan Theriot, who went hitless for St. Louis in Game 7 of last year's Series, singled softly into right field off Phil Coke opening the 10th.

Brandon Crawford sacrificed, nearly bunting the ball past Coke. Angel Pagan struck out and Scutaro singled into short center field as Theriot slid home ahead of Austin Jackson's throw.

CELEBRATING A CHAMPIONSHIP

Giants fans gathered  in downtown San Francisco to celebrate their team's World Series championship.

Some 2,000 fans assembled to watch the game on a Jumbroton a park across from City Hall, but the crowd grew in numbers and volume throughout the night.

The crowd exploded in a roar with the final out as the Giants defeated the Detroit Tigers, sweeping the series.

10-year-old Anthony Yos and his 15-year-old brother Luciano danced in an embrace with their parents.

Someone in the crowd launched fireworks a few minutes after the game and the park was awash with revelers, strangers hugging strangers and wine bottles and marijuana cigarettes being freely passed through the crowd despite a heavy police presence.