PHILADELPHIA – Nick Castellanos experienced the greatest feelings in the world on Sunday night at Citizens Bank Park.

He might have saved the Phillies’ season, hitting a walk-off single to left field to score Trea Turner from second base in a 7-6 victory over the Mets in Game 2 of the National League Division Series. Castellanos’ fifth walk-off hit of the year – and the first of his postseason career – evened the best-of-five series, stealing momentum from a New York team that had not stopped finding ways to win games in improbable fashion for the past week.

Castellanos reached first base, dropped his helmet, raised his arms and turned to his teammates to celebrate.

Moments later, he sprinted to his son Liam behind home plate.

“Let’s go!” father and son shouted at one another.

“The best,” Castellanos said. “Because when I’m old and no one cares about me as a baseball player anymore, we’re going to be at home and be able to remember and look back at that.”

There is no chance the Castellanos family will not remember everything that happened in Game 2. In so many ways, it represented his entire season. He batted .194 with four home runs, 17 RBIs and a .556 OPS through May 18, ranking 140th out of 144 players in OPS (minimum 150 plate appearances).

He answered countless questions back then about his swing and his approach. He answered countless questions about taking a mental break.

But Castellanos played on. He fought. He batted .278 with 19 home runs, 69 RBIs and an .818 OPS from May 19 through the end of the regular season. He worked his way up the Phillies’ lineup, starting the season hitting seventh and finishing hitting fourth behind Bryce Harper.

That’s where Castellanos found himself in Game 2.

The Phillies’ offense had been virtually nonexistent in the NLDS when Castellanos hit in the fourth inning. They had been chasing pitches out of the strike zone again – swinging at nearly 48.5 percent of pitches out of the zone through five scoreless innings – which was a major reason for the team’s flameout in the 2023 NL Championship Series. Castellanos finished the NLCS hitless in his last 23 at-bats and 1-for-24 overall, which never seems to be far from anybody’s mind when he struggles.

Castellanos got booed when he swung at consecutive pitches down and away to fall behind 0-2 to Mets right-hander Luis Severino. He took a third consecutive pitch down and away for a ball.

Fans mockingly cheered him.

Castellanos shook his head. He appeared to mutter something.

“I had a lot of thoughts going through my head,” he said. “Just kind of frustrated, so I guess I locked in more.”

He grounded out on a fourth consecutive pitch down and away.

“It’s not how you start, it’s how you finish,” Castellanos said.

• Phillies-Mets NL Division Series Game 3 FAQ (Tues., 5 ET, FS1)

Harper crushed a two-run homer to center field in the sixth inning against Severino to cut the Phillies’ deficit to 3-2. The blast electrified the crowd. He rounded the bases, stepped on home plate, shouted and gestured to the fans.

Castellanos kept up the good vibes, hitting an 0-1 sweeper to left-center field for a game-tying solo home run.

“I'm so happy for him because I know that there's been a lot of talk about chase and this and that,” Phillies manager Rob Thomson said. “But he can hit. He can hit. He's just been grinding all year.”

Brandon Nimmo hit a go-ahead homer against Orion Kerkering in the seventh. But the Phillies scored three runs in the eighth to take a 6-4 lead. Bryson Stott, who was celebrating his 27th birthday, laced a 3-2 slider down the right-field line. Harper, who had walked, strolled home from third to score the tying run. Castellanos, who had singled, sprinted from first to score the go-ahead run.

“He continues to fight and work,” Harper said about Castellanos.

The Phillies scored another run to take a 6-4 lead. They thought they had the game in the bag, but Phillies left-hander Matt Strahm allowed a two-run homer to Mark Vientos in the ninth to tie it.

It’s not how you start, it’s how you finish.

Mets right-hander Tylor Megill walked Turner and Harper with two outs in the bottom of the ninth. Castellanos stepped into the batter’s box. He said he often has feelings he might do something special in moments like that. He said he had that feeling in the ninth.

“And then usually I chase out of the zone and have to get rid of them and settle back in,” he said.

Castellanos swung at two pitches just off the plate to fall behind 0-2. He took a slider in the dirt for a ball.

Megill followed with another slider. He hung it.

Castellanos smoked it. He gave the Phillies life. Teams that have a 2-0 lead in a best-of-five series have won the series 80 of 90 times (89 percent). But when the series is tied after two games in the current 2-2-1 Division Series format, the home team has won 66 percent of the time.

They’re not great odds, but it would have been way worse without Castellanos’ heroics. His five walk-offs between the regular season and postseason are tied for the third-most in a single season since 1974. Only Edgar Renteria (six in 1997 with Miami) and Andre Ethier (six in 2009 with Los Angeles) had more.

“Unfazed,” Strahm said about Castellanos. “I mean, the beginning of his season and how he turned it around and showed everyone how Nick can go through anything, I mean, he’s a veteran for a reason.”

“He's Nick Castellanos,” Stott said. “He’s a professional hitter, and he's hit his whole career. He came up big for us a lot this year. It feels like every walk-off hit is Nick, and that's who he is.”