HOUSTON — Shaking off a foul ball he took to the mask earlier in the game, Philadelphia Phillies catcher J.T. Realmuto hit a tiebreaking home run in the 10th inning, leading to a stunning 6-5 victory against the Houston Astros in Game 1 of the World Series on Friday night.

“Just ecstatic to put a good swing on that pitch, be able to give our team the lead,” Realmuto said after the dramatic win. “We did such a good job fighting back there.”

The Phillies scored six runs after trailing 5-0 early in the game, becoming the sixth team all time to overcome a five-run deficit to win a World Series game. Astros manager Dusty Baker has been on the losing end on the past two, with the other coming with the 2002 San Francisco Giants in a loss to the Angels.

The Phillies’ second time through the order Friday night against Astros ace Justin Verlander proved to be fruitful as Philadelphia scored three runs off him in the fourth and two more in the fifth to tie the score at 5. Verlander was perfect through the first three innings.

“I think the second time [through] you’ve seen it once,” Phillies manager Rob Thomson said of Verlander’s pitches. “So there’s some familiarity there. So I think that’s why we had some success off him the second time.”

The Astros jumped to a lead thanks to two home runs in back-to-back innings by right fielder Kyle Tucker. After the Phillies tied the score at 5-5 on a two-run double by Realmuto in the fifth, Thomson managed the rest of the night with urgency, beginning with his decision to bring in reliever Jose Alvarado in the fifth inning.

“I think once we scored the three you were kind of feeling it,” Thomson said. “Like, we got back in this thing, now the momentum has changed. And that’s really why I went to Alvarado in the fifth inning, which I haven’t done all year, because I thought that the momentum changed there. [It] was so important to keep that momentum, get through those guys, and we’ll figure out the rest later.”

The Phillies’ bullpen was spectacular, throwing 5⅔ shutout innings as Thomson used all of his high-leverage arms, including scheduled Game 3 starter Ranger Suarez.

“So what went into it was, today’s a side [bullpen] day for Game 3, so we thought, OK, we’ve got that one pocket, Alvarez to Tucker, that’s a pretty big pocket, and thought, we’ll put him in if that situation comes up,” Thomson said. “If not, that’s fine. And it came up.”

Thomson didn’t rule out Suarez for Game 3 after he threw just 11 pitches on Friday. His performance helped bridge the gap to the late innings, with Seranthony Dominguez getting two outs in the eighth and three in the ninth to pitch the Phillies into extras.

But a single and stolen base by Jose Altuve put the winning run on second in the bottom of the ninth. That’s when shortstop Jeremy Pena blooped a ball into right field, where Nick Castellanos made a magnificent, inning-ending sliding catch to preserve the tie.

“I felt like I read the swing pretty well, and as soon as I saw the direction of the ball I felt like I got a good jump on it,” Castellanos said.

Castellanos took a few steps in after Altuve reached second. Those extra yards proved to be helpful as he closed the gap on the ball.

“I just thought he had a better chance of trying to bloop something in there than torching something over my head,” Castellanos said. “So that was kind of my thought process there, just thought of it on the fly.”

The catch kept the game alive for Realmuto’s heroics in the 10th. He deposited a 3-2 fastball by Astros reliever Luis Garcia into the right-field stands, sending his dugout into a frenzy.

It’s a moment Realmuto said he has imagined since he was a kid.

“I mean whiffle ball games in the backyard, the whole 3-2, bases-loaded, two-out situation,” he said. “I probably had 7,000 at-bats in that situation growing up.”

It almost never came Friday after Realmuto took a foul ball to the mask, leading to a delay as the Phillies’ training staff attended to him. He stayed in the game.

“Honestly, my head wasn’t the problem,” Realmuto said. “It just smoked my jaw pretty good. It’s probably not going to be very easy for me to eat dinner tonight, but as long as my head’s OK, I’ll be good to go.”

The Astros left the tying and winning runs on base in the bottom of the 10th as Tucker struck out and pinch-hitter Aledmys Diaz grounded out.

Realmuto is the first catcher with an extra-inning home run in the World Series since Carlton Fisk’s walk-off homer in Game 6 of the 1975 series.

Castellanos was asked what the vibe in the dugout was after his team went down 5-0.

“Let’s go to work,” he said. “We’ve been there before. I think that’s what this team does so well. We know there’s no quit, really. We really respect all 27 outs and we take that seriously, and we take it personal.”

The loss was the first for the Astros this postseason.

Game 2 is Saturday night. The Astros will start lefty Framber Valdez, and the Phillies will counter with right-hander Zack Wheeler.