MILWAUKEE — The San Francisco Giants’ lineup card Thursday afternoon listed Casey Schmitt as the left fielder and leadoff hitter — two places that no living and sober soul, Schmitt included, could have envisioned when the season began a little over two months ago.Schmitt has been the Giants’ most productive hitter. He’s made major strides in his two-strike approach. He’s doing enough damage at the plate to be a legitimate All-Star candidate, even if he might as well be the Peace and Freedom candidate on the designated hitter ballot with Shohei Ohtani. As a leadoff guy, though, he appears as miscast as John Travolta in “Battlefield Earth.” He’s drawn just seven walks. He doesn’t see a ton of pitches per plate appearance.But the Giants had a problem that lacked a solution. They entered Thursday with a major league-worst .262 on-base percentage from the leadoff spot. The way they figured it, at least Schmitt has been making something happen in his at-bats all season. When you’re trying to set a tone, you could do worse than to start the game with your best action guy at the plate.Schmitt created action on the first pitch. He lofted a drive that slipped past the outstretched glove of Milwaukee Brewers left fielder Jackson Chourio, hit the yellow padding on the top of the fence and bounced over for his career-best 13th home run of the season. It was a lid-lifting swing to what became a three-run inning, and that rally was merely the opening act in a 20-hit performance as the Giants earned a four-game series split with a 12-9 victory at American Family Field.The Giants received 10 of those 20 hits from their Nos. 5-7 batters. Jung Hoo Lee continued to be the toughest out in the major leagues this week, going 4-for-5 to extend a 12-game hitting streak in which he’s batting .521. Bryce Eldridge, the 22-year-old rookie DH ballyhooed for his power, demonstrated yet again that he’s far more than a one-dimensional hitter while reaching base four times and taking one professional plate appearance after another. And Matt Chapman, batting seventh while he tries to emerge from a season-long slump, collected his first three-hit game since April 17, including two that drove in runs.Catcher Eric Haase, the No. 8 batter, only finished with one hit, but he made it count. His grand slam in the seventh inning was the third of his career, and it blew open the game, but only for the moment, because the Giants’ bullpen nearly gave it back in the ninth.Right-hander Wilkin Ramos didn’t retire any of the four batters he faced, and the Brewers brought the tying run to the plate against Caleb Kilian. Milwaukee’s David Hamilton gave the home crowd a momentary thrill when he hit a deep drive to center field, but defensive replacement Jonah Cox ran it down on the warning track and allowed the visiting dugout to exhale.The Brewers’ near comeback also transformed center fielder Drew Gilbert’s seventh-inning home run robbery of Andrew Vaughn from a feel-good highlight play into what might have been a game-saving catch. Gilbert, who might be 5-foot-10 in spikes, leapt at the wall like a 6th-grader trying to dunk a basketball and got enough air underneath him to reach over the top of the fence and turn a two-run homer into an inning-ending catch.