Posey, the only player in the starting lineup when San Francisco win the 2010 clincher at Texas, celebrated with his teammates in the center of the Comerica Park diamond. In the clubhouse, they hoisted the trophy, passed it around and shouted the name of each player who held it.
"World Series champions!" hollered outfielder Hunter Pence, who started the pregame seed-tossing ritual.
Pablo Sandoval, nicknamed Kung Fu Panda, was benched for most of the 2010 Series and then went 8 for 16 this year, including a three-homer performance in Game 1, to win MVP honors.
"I was ready for the moment," he said. "I was waiting for the opportunity to be in the playoffs again."
Cabrera delivered the first big hit for Detroit, interrupting San Francisco's run of dominant pitching with a two-run, wind-blown homer over the right-field wall in the third.
Posey put the Giants ahead 3-2 with a two-run homer in the sixth and Delmon Young hit a tying home run in the bottom half.
San Francisco then won a battle of bullpens.
Ryan Theriot led off the 10th with a single against Phil Coke, moved up on Brandon Crawford's sacrifice and scored on a shallow single by Scutaro, the MVP of the NL championship series. Center fielder Austin Jackson made a throw home, to no avail.
"We were very adamant that we have to step on their throats," Giants pitcher Barry Zito said. "We saw what they did to New York."
Santiago Casilla got one out in the ninth for the win. Romo struck out the side in the bottom of the 10th for his third save of the Series.
The Giants finished the month with seven straight wins and their seventh Series championship. They handed the Tigers their seventh straight World Series loss dating to 2006.