SAN FRANCISCO >> Anthony DeSclafani raised his eyebrows. He knew Monday was Patrick Bailey’s birthday, but he had no idea what age the rookie catcher had turned.

“He’s 24? Really?” DeSclafani said. “Jeez.”

Bailey is young, but in many ways this birthday showed how he plays beyond his rookie status in the Giants’ 14-4 trouncing of the Pittsburgh Pirates in front of a robust Memorial Day crowd at Oracle Park.

First, the highlight plays. Bailey was one of six Giants to record a multi-hit game against Rich Hill and the Pirates bullpen. He was one of two to hit a homer.

His second career home run in 10 big league games was his first at Oracle Park and his first as a left-handed hitter.

His three-hit day also included a key two-run double (reaching third on an error) in the Giants’ five-run second inning. That hit took some disciplined approach from a less-familiar right side of the plate, shortening his swing to slap Hill’s curveball the other way.

Bailey raised his average to .355 with a 1.050 OPS. With fellow rookie Casey Schmitt above him in the lineup adding three hits — raising his average to .342 with a .851 OPS — the home crowd got a prime seat to watch this team’s next generation start to grow its roots. Even with the youth movement’s small sample size, it’s a drastic shift from a 2022 season in which the Giants boasted a boring and mediocre big league team with little movement happening in the minor leagues.

There’s palpable excitement in the clubhouse around the momentum that’s started with these two prospects.

“It’s unusual,” manager Gabe Kapler said. “It’s unusual to see two rookies come up and have the type of success and sustained success that these two player are having.”

That success is happening between the lines, too. Bailey’s intuitive, cerebral qualities behind the plate for which the Giants drafted him three years ago came to play during a sixth inning pitch clock snafu.

DeSclafani was penalized for a pitch clock violation with Bryan Reynolds at the plate when he stepped off the mound. Bailey later admitted it happened because he had issues with the PitchCom technology in his ear. DeSclafani could only marvel at how Bailey turned a mishap into a positive.

After two uncompetitive pitches called for a ball, Bailey came to the mound to apologize for the tech mishap and to give his starter a breather. DeSclafani wanted to talk it out.

“What do you got? Think they’re swinging 2-0?” he asked.

“They’re fairly aggressive,” Bailey said.

The pair agreed to throw a slider, hoping to get Reynolds swinging into a ground ball. Sure enough, Reynolds grounded into a double play on a ball up to second baseman Schmitt.

“Very young but seems mature beyond his years,” DeSclafani said. “It feels like he’s been doing this for a while. Great quality to have and it seems like he carries that confidence behind the dish.”

Plenty of other Giants got in on the action, including recently-activated Austin Slater. His 410-foot home run was the final touch on that five-run second inning and he finished the game with three hits and four RBIs batting leadoff.

Giants hitters were all over Hill’s curveball, which wasn’t dropping far enough out of the zone to generate swings and misses. Brandon Crawford’s three-hit day included a hit off a sweeper that bounced over first base for a standup double. It was a standout game for Crawford, who sat for three of the Giants’ seven games on the road trip due to hitting struggles

The Pirates took an aggressive approach against DeSclafani from the jump. Each of their first three batters swung at his first offering — and all three made contact, resulting in a three-pitch inning that ended with Tucupita Marcano, who reached on a leadoff double, being doubled off due to a bad read of Andrew McCutchen’s shallow fly ball. Marcano was headed for home plate as center fielder Bryce Johnson tossed the ball to second to end the inning.

DeSclafani cruised until the seventh inning, when he gave up two runs — including a Jack Suwinski home run. But he finished the inning, giving up three runs on eight hits with no walks and two strikeouts on the day.

The game ended with position players pitching on both sides. Chris Owings pitched the eighth for the Pirates and Brett Wisely pitched the ninth for the Giants — giving up a home run to Suwinski.

This was the Giants’ 11th win in 14 games.