SAN FRANCISCO — It had been almost 18 months since he last set foot in this ballpark, for an ill-fated free-agent meeting two winters ago. Decades had past since he passed through the turnstiles as a young fan. Never before had he taken swings from its right-handed batter’s box.

Aaron Judge didn’t know what to expect.

“But I didn’t mind it,” the Yankees’ 6-foot-7 outfielder said with a sly grin.

Judge was greeted Friday night with multiple, hearty rounds of boos from the 35,018 fans who paid for the opportunity to give a piece of their minds to the Giants’ former free-agent flame, and the Northern California-born slugger responded by launching his 12th and 13th home runs of the month, driving in four runs while handing his onetime suitors a 6-2 loss.

With the Bronx Bombers visiting Oracle Park for the first time since 2019, the home fans took full advantage of their first chance to air their grievances since Judge became the latest superstar to spurn the Giants’ advances, opting to re-sign with the Yankees for $360 million over nine years in December 2022.

For Judge, who grew up about 90 minutes east in San Joaquin County, the homecoming carried a different meaning. Family and friends filled “a couple” suites, he said.

“You dream about it in the backyard, playing around a little bit,” Judge said, towering over about a dozen reporters in the visitors’ clubhouse. “It’s a special place. I grew up a Giants fan. I loved coming to games out here. It was pretty cool being on the opposite side being on the field now.”

Rounding the bases after his first home run, a three-run shot into the left-field bleachers, Judge said he peered into the grandstands where the ball landed and recounted the times he sat in the same area. He provided two home run calls, albeit for the visitors, to Duane Kuiper and Mike Krukow — “Kruk and Kuip,” he said, “I’ve heard them for years call the games and hear all the homers that Barry (Bonds) hit here.”

As he rose through the ranks, from Linden High on to Fresno State, Judge was never granted the opportunity to play at the Giants’ home ballpark. When the Yankees last visited five years ago, Judge was in the middle of a two-month absence with an oblique strain and wasn’t able to play.

“So that was the first time digging in,” he said. “This is baseball right here.”

As the Giants attempted to lure the slugger two winters ago, they wondered about the potential impact of playing 81 games a year in their home park that had shown a tendency to sap power, particularly from right-handed hitters. Judge left little doubt, sending his first homer 394 feet to left and his second 426 to center.

Before the game, though, Judge found himself wondering the same.

“I didn’t hit any home runs in BP. So I was a little nervous,” he said. “Barry and a lot of those guys back in the day made it look pretty small at times. I had a lot of fun hitting BP today for sure. … I think it was more the pregame anticipation. Once you step between the lines and dig in there and you’ve got (Giants starter) Jordan Hicks out there throwing a nasty sinker, you’ve got to lock in and treat it like a baseball game.”

The Giants gave it their best pursuit, even hosting Judge for a two-day affair, but he chose the chance to become a Yankee legend over a hometown hero. The Yankees are on top of the American League, and Judge on top of many of the offensive leaderboards, so the decision has worked out all right so far.

“It was close,” Judge said. “I’ve said it the past couple years. It was a while ago, but it was pretty close. They’ve got a great organization here and a great team. Great pitching staff. Great young guys coming up. I obviously ended up going to New York.”