HOUSTON -- J.T. Realmuto homered in the top of the 10th inning to give the Phillies a surprising comeback 6-5 win in Game 1 of the World Series, but he never would have had a chance to swing the bat had Nick Castellanos not made the most important catch of his career.

“We've been there before. I think that's what this team does so well. We know there's no quit, really,” Castellanos said after his club scored six unanswered runs to bounce back from a 5-0 deficit. “We really respect all 27 outs and we take that seriously, and we take it personal.”

In the bottom of the ninth inning of a 5-5 game against reliever Seranthony Domínguez on Friday, the Astros made a two-out push when Jose Altuve blooped a single to no-man’s land between three players in center field.

Representing the go-ahead run as Jeremy Peña batted, Altuve stole second base on the first pitch from Domínguez. A very close safe call was upheld on a replay challenge from the Phillies.

Ahead of the next pitch, Castellanos moved closer to the infield. According to data, the average right fielder vs. right-handed hitters at Houston plays 288 feet from home plate and 289 feet for Peña.

Castellanos moved in 20 feet to be exactly 267 feet away.

“I don't know, that was just what my instincts told me to do,” Castellanos said. “I just thought he had a better chance of trying to bloop something in there than torching something over my head. So that was kind of my thought process there, just thought of it on the fly.”

Peña did just what Castellanos anticipated. He lifted a fly ball near the line in short right field. Castellanos ran in and to his left before making the sliding catch on his back for an improbable third out to force extra innings. While not known for his defensive prowess, his best direction is coming in and to his left, according to Outs Above Average, which rated him as average this year.

“The moments of importance [are] kind of established before the ball's even hit,” Castellanos said. “And then once it's coming my way it's … just kind of instincts take over.”

“Oh, man,” Phillies left fielder Kyle Schwarber said before adding a whistle. “I was going like this the whole time, ‘Get there, get there, get there, get there.’ He makes this sliding catch, and it obviously saves the game and extends the game for us. I can’t say enough about how he’s playing right field. He’s made some unbelievable catches out there in some really big positions to keep the game going. He’s been doing a phenomenal job out there.”

Said Castellanos to FOX: “I think that a lot of times I have trouble keeping attention during the regular season every day for nine innings, but with the postseason, this kind of baseball is incredible, you don’t have a choice but to be locked in, watching swings, watching balls come off the bat, I think that’s just kind of why I’m playing better.”

According to Statcast, the ball had a 65 percent catch probability -- for a three-star catch -- but Castellanos was 5-for-55 on three-star catch attempts this season. This time, he made one the Phillies absolutely had to have to keep the Astros from walking off with a Game 1 victory.

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“When the ball was first hit, I thought it was hit so softly that I didn't think he was going to get there,” Realmuto said. “I thought the game was over. But then I saw him charging in, coming in hot, and I thought, ‘Oh, man, he might have a chance to catch that.’”

The snag brought flashbacks to another great grab made in this postseason. In Game 1 during the National League Division Series vs. the Braves, Castellanos made a similar catch for the second out of the ninth inning to help preserve a 7-6 victory.

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“Yeah, just reminded me of Atlanta, you know? It makes you feel good because that was a pretty good result in that game too,” Phillies manager Rob Thomson said.

Castellanos, 30, opted out of his contract with the Reds after last season and signed a five-year, $100 million free agent deal with Philadelphia. Originally, he wasn’t expected to play as much in right field as he had in Cincinnati. But with Bryce Harper dealing with a right elbow injury most of the year and unable to throw, Castellanos made 119 regular-season starts in right field out of his 136 games played.

“I think the plan originally was that it was going to be a revolving door with me and Kyle in left, and then Bryce was going to get one or two days off a week because the goal was for everybody's legs to be as fresh as possible,” said Castellanos, who also had an RBI hit and scored during the Phillies' three-run fourth inning. “And then, you know, baseball happens and [Harper] ended up having that injury, and I gladly accepted the role of just being out there every day.”