Verlander was chased after allowing five runs and six hits in four innings, his shortest start this year. He threw 98 pitches, and Detroit manager Jim Leyland could alter his rotation and start him in Game 4 on short rest instead of Max Scherzer. That would enable Verlander to pitch a possible Game 7, again on three days' rest.
Verlander was 0-2 as a rookie in the 2006 Series against St. Louis but had been superb this October, entering with a 3-0 record and a 0.74 ERA.
Sandoval hit the first bases-loaded triple in All-Star game history off Verlander in July, and kept on going against the reigning AL MVP and Cy Young Award winner.
He connected on a high 95 mph pitch with an 0-2 count in the first inning and sent the ball just over the wall in right-center. Then, on the very next pitch after a mound visit by Tigers pitching coach Jeff Jones in the third, Sandoval hit a two-run, opposite-field drive into the seats in left for a 4-0 lead. Verlander simply said, "Wow!"
Sandoval had been benched for four of five games in the Giants' 2010 Series win over Texas when he entered in a 3-for-14 slide. The Giants then told Sandoval, nicknamed Kung Fu Panda for his roly-poly physique, to get in shape or start the next season in the minor leagues.
Winning by home run is unusual for the Giants, whose 103 home runs were last in the major leagues. The only other three-homer game at the ballpark was by the Los Angeles Dodgers' Kevin Elster in the very first opener, in 2001. The last three-homer game by a Giant was Aubrey Huff at St. Louis in June 2011.
Angel Pagan had another of the Giants' unusual postseason hits with two outs in the third when his one-hopper kicked off the corner of the third-base bag and ricocheted past Cabrera at almost a right angle into short left field. Marco Scutaro, who struck out just once in 48 at-bats during the NL playoffs, fouled off two 98 mph full-count pitches and lined a single into center field to bring up Sandoval.
Zito, dropped from the Giants' roster for the 2010 postseason after a four-year slump, finally justified the $126 million, seven-year contract the Giants gave him after the 2006 season. The 2002 AL Cy Young Award winner was helped when left fielder Gregor Blanco made neat diving grabs of liners by Cabrera in the third and Prince Fielder in the sixth.
In addition, Zito added an opposite-field RBI single to left in the fourth. After getting just four hits during the regular season, Zito has singles in consecutive postseason appearances.
Tim Lincecum, who won twice in the 2010 Series, came out of the bullpen with two on and two outs in the sixth and struck out Jhonny Peralta.
Coming off its first AL pennant since 2006, Detroit had nearly a week off after sweeping the New York Yankees in the AL championship series. San Francisco had just a day to rest after overcoming a 3-1 deficit against defending champion St. Louis in the NLCS.
The winner of the opener has claimed the title 66 of 107 times, including eight of last nine. The NL is seeking to win three straight Series for first time since 1979-82.
Madison Bumgarner, 0-2 with an 11.25 ERA for the Giants in two postseason outings, starts Game 2 on Thursday against Detroit's Doug Fister, who has a 1.35 ERA with no decisions in two postseason appearances this year. The Series then shifts to the Motor City for Game 3 on Saturday.