To be certain, the San Francisco Giants’ starting rotation should be withering, in tatters, as it seemed on the verge a week ago. Barry Zito’s a has-been. Ryan Vogelsong’s a never-was. Tim Lincecum has been bumped to the bullpen. Matt Cain had to hold it all together with a well-used right arm. And Madison Bumgarner? Where had he been the past 10 days?

“I’ve been struggling a little bit,” he said.

No more. Bumgarner tweaked his mechanics and reinvented himself as a stud, which currently helps him fit in with a unflappable Giants starting staff. The 23-year-old left-hander delivered seven innings of two-hit ball in San Francisco’s 2-0 victory over Detroit in Game 2 of the World Series on Thursday, and the Giants somehow cobbled together a run in the seventh against equally stout Doug Fister — who took a line drive directly off his head, yet kept on pitching.

Fister’s effort — pitching into the seventh of a then-scoreless game after taking Gregor Blanco’s liner and all but heading it into shallow center field — fell somewhere between alarming and admirable. Game 2, as it transpired, was about the two starting pitchers, because Fister matched Bumgarner by at one point retiring 12 consecutive Giants.

But because Game 2 ended as it did — with the Giants scoring the winning run in the seventh on a blessed-by-the-gods bunt and a bases-loaded double-play ball — the series is now about the Giants and their starting pitching, which flew to Detroit with a two-games-to-none lead.

“I came in with the mind today that today was going to be the biggest game of the series,” said Blanco, who started a key relay to gun down a Tigers’ threat at the plate, then laid down the bunt in the seventh that loaded the bases and set up the winning run. “I think if we win this game, they’re going to feel under pressure after this. The way we’ve been playing, we’ll see what happens in Detroit.”

What is sure to happen: The Giants will roll out a starting pitcher who feels great about his last start. Since Zito replaced Bumgarner, who began the postseason with two poor outings, for Game 5 of the National League Championship Series, San Francisco starters have gone 5-0. They have allowed two runs in 33 innings, a 0.55 ERA. And now Bumgarner, once banished, is back in the act, because through seven innings he struck out eight and faced two men more than the minimum.

“Over the last three years, the pitching’s been strong enough that it keeps the team on its toes,” General Manager Brian Sabean said, “because they know they have a chance to win almost every single game.”

They are doing so at the moment. Win 8-3 behind the power of Pablo Sandoval’s three homers, as the Giants did in Game 1, and the AT&T Park crowd can relax. Win 2-0 behind pitching, as the Giants did in Game 2, and the fans must decide whether to stand and shout or sit and squirm.

“It’s our style, really,” Giants Manager Bruce Bochy said. “It’s been like that for a few years here. We play a lot of close games, and these guys are used to it.”

Thursday’s game was close because of Bumgarner and Fister, who faced very different threats in the second — and not much else. Bumgarner’s was of the traditional sort, when Blanco had a bit of trouble digging out Delmon Young’s screaming grounder into the left field corner. With Prince Fielder, all 275 pounds of him, thundering around from first, Tigers third base coach Gene Lamont told him to go.

“I think Gene just got a little over-aggressive,” Tigers Manager Jim Leyland said.

But it was close, and it took good fortune. Blanco threw toward relay man Brandon Crawford, the shortstop, and the ball went over his head — right to second baseman Marco Scutaro, who was backing up. Scutaro fired home, and Buster Posey’s sweeping tag caught Fielder — whose left foot appeared to catch in the dirt — in an area that was difficult to miss: his rear.

That cut down the Tigers’ only real scoring chance of the night. Bumgarner never again allowed two base runners in an inning.

“He just had a pretty determined look on his face tonight,” Leyland said.

Fister, though, was just as determined. Blanco’s liner came with two outs and a man on in the second. Nothing — not Fister’s glove, not his hand, not a stray mosquito — got between the ball and Fister’s head.

“I was scared to death,” Leyland said.

Immediately, Fister began answering questions from athletic trainers to determine his fitness to remain in the game. He struggled neither with those answers nor with the Tigers hitters. Leyland finally came and got him after Hunter Pence sent his 115th pitch into left field for a single that led off the seventh.

That set up the winning rally off Detroit reliever Drew Smyly, a left-hander sent in to face three consecutive left-handed hitters. He walked the first, Brandon Belt, to get to Blanco. At 3-1, he tried to bunt a fastball for a sacrifice. It headed to the third base line — and stopped there. An out became a hit to load the bases.

“I wasn’t really trying to do that,” Blanco said. “I guess it was meant to be.”

At the moment, that’s how this postseason feels for the Giants: meant to be. With no one out, Leyland elected to play his infield back.

“We felt like we couldn’t give them two runs,” he said, and when Crawford came up and hit a grounder to second, the Tigers had their double play — but allowed Pence to score. The Giants tacked on an insurance run. The Tigers never got another base runner.

“Always, you want to have luck,” Blanco said. “That’s what we have right now.”

That, and starting pitching. In whatever order seems fit.