SAN FRANCISCO -- A common saying in baseball is that hitting is contagious. As it turns out, putting up zeros can be equally as infectious in a big league 'pen.

Five Giants relievers shut down the highest-scoring offense in baseball, blanking the Phillies, 1-0, in Tuesday night's walk-off victory in 10 innings. It was only the second time Philadelphia had been shut out in 2024.

"We were actually talking down there early on like, 'The boys are locked in,'" said Sean Hjelle, who pitched the final two innings and earned the win. "I think it's just one of those things where it's like, you see the guy in front of you go out there, execute pitches and get outs, and do it efficiently.

"You're like, 'I don't want to be that guy that breaks it up.' It's contagious from the guy in front of you, and then you just try to take that and pass it on behind you."

Through the first nine innings, the Giants had nothing going against Zack Wheeler and a trio of Phillies relievers. The scoreless tie lasted until the bottom of the 10th, when Luis Matos lifted a sacrifice fly just deep enough to left field for Tyler Fitzgerald to score from third base.

San Francisco secured a series win against Philadelphia and has the chance to go for the sweep on Wednesday. The Giants were swept in four games at Citizens Bank Park from May 3-6, putting them a season-high-tying six games under .500 at the time.

Throwing a bullpen game against Wheeler was a bold move -- especially because San Francisco relievers covered the final five frames of Monday's win -- but one that ended up paying off.

“If you can’t get to him, you want to try to drive his pitch count up," manager Bob Melvin said. "We did that after the second inning to where you can get him out of the game. And the way we’ve been scoring off bullpens, it feels like a win when he comes out of the game and you’re not behind.”

The Giants set the tone for a strong evening on the mound early on, with Erik Miller -- a fourth-round Draft pick of the Phillies in 2019 -- serving as the opener for the third time this season. Taylor Rogers was up next, chipping in two innings before giving way to Spencer Howard, who scattered five hits across four frames to become the first Giants reliever to toss at least four innings without allowing a run in his team debut since Jakob Junis on April 22, 2022.

"The most value I could provide is to eat the most amount of innings, save the 'pen," Howard said. "Just go after guys, put the ball in play and hopefully get quick outs."

Like Miller, Howard was a Phillies Draft pick, selected in the second round in 2017. The 27-year-old right-hander made his Major League debut with Philadelphia in the pandemic-shortened 2020 season.

"I was excited, good to face guys that you know a little bit," Howard said of facing his former team. "Obviously, the team's changed a decent amount since I was there. But yeah, fun to see some familiar faces in the box."

With Ryan Walker and Camilo Doval both logging three appearances in the prior four days, Tyler Rogers and Hjelle were on tap for the late innings. Rogers, who allowed three runs in the ninth inning for a blown save on Sunday in New York City, worked around a hit for a clean eighth inning.

Hjelle, who has enjoyed a breakout beginning to the season, was entrusted with the ninth inning and came back out for the 10th. After his two scoreless innings on Tuesday, his ERA sits at 2.95 as he continues to earn opportunities to pitch in high-leverage situations.

"The confidence that BoMel's put in me and the rest of the staff, and the guys to rally behind me -- hell, that's all I need, really," Hjelle said. "It's incredible. The guys are playing awesome right now, and it's just contagious."

That was the word of the night for Hjelle following the walk-off win.

"It's just from one guy to the next, it's just bleeding over," he said. "It's a great time to be playing Giants baseball right now."