SAN FRANCISCO -- The hero of the night started the game on the bench.

For the second consecutive game, manager Bruce Bochy opted to start the hot-hitting Pablo Sandoval at third base over the struggling Evan Longoria. But Longoria broke out of his slump in a big way, delivering a go-ahead, three-run double to lift the Giants to a 3-2 comeback win over the Dodgers in Monday’s series opener at Oracle Park.

“It was outstanding,” right-hander Jeff Samardzija said. “Great to see Longo go out there and get a big hit. We see that guy working every day and how much he loves this game. He loves this team. Sometimes it’s tough. You press and press and press and you want it to happen. And finally he went out there today and had a huge hit in a big game.”

The Giants hadn’t originally intended for Longoria to find himself in that situation. Sandoval has established himself as one of the club’s biggest offensive threats over the first month of the season, but he tweaked his right knee against the Yankees on Sunday and couldn’t swing from the right side. When Dodgers manager Dave Roberts brought left-hander Scott Alexander into the game in the sixth inning, Bochy was forced to replace Sandoval with Longoria.

“We were caught there,” Bochy said. “Pablo couldn’t swing right-handed tonight. The knee had a little swelling to it from a play yesterday, but it worked out well.”

Longoria flew out in the sixth before coming up to bat in the seventh with the bases loaded, two outs and the Giants trailing by two. He stepped into the box against Dodgers right-hander Dylan Floro, who had not allowed a run in 11 1/3 innings to start the year.

Longoria got ahead in the count, 2-0, before fouling off a sinker on the inside corner from Floro. Floro came back with another sinker inside, but Longoria shot it into the left-field corner for a bases-clearing double. It was the signature moment that Longoria had been seeking with the Giants since coming over from the Rays in a December 2017 trade.

“I’ve been waiting for that hit in a Giants uniform for a long time,” Longoria said. “More than a year.”

Longoria entered Monday batting just .204 with a .610 OPS and eight RBIs, so he understood the Giants’ decision to deploy Sandoval at third base against two consecutive right-handers.

“I’m here to win, and whoever gives us the best opportunity on that given day, I’m all for that,” Longoria said. “I’m ready off the bench and happy to get an opportunity late there. I think that has to be the mentality for everybody. When you get your chance to play, be ready to go. I’m hitting .200, so it’s not something that I can really go into the office and say, ‘Hey, why Pablo?’ Pablo’s been good, so we’ll ride the hot hand and be ready when you get the opportunity.”

Longoria’s breakthrough couldn’t have come at a better time for the Giants, who were coming off a deflating three-game sweep at the hands of the Yankees over the weekend.

Bochy acknowledged afterward that the Giants would have to approach their series against the Dodgers with greater urgency than usual for an April matchup. After sinking to the bottom of the National League West, they could ill afford to cede more ground to the first-place Dodgers and drift further from contention.

Longoria made sure that didn’t happen on Monday.

“We’ve got a lot of work to do,” Longoria said “Every win, every big hit in those situations is big right now.”