MILWAUKEE — Mets first baseman Pete Alonso camped out under a high pop-up in the seventh inning at American Family Field on Thursday. As he reached up to catch the ball, it bounced off his glove and landed in the net in foul territory.

Early in the inning, the Brewers took a 2-0 lead on back-to-back home runs, causing chaos in Dome Stadium. When Alonso dropped the pop-up, Milwaukee seemed destined for victory. The crowd sensed it and grew louder.

But Alonso didn’t let that deter him.

“Next game, next pitch. Whether it’s defense or attack, focus on the next one,” said Alonso, his focus turning to the next one after the botched game. “You can’t dwell in the past.”

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At this point, Alonso was having trouble with the plate and went 1-8 in the series. He hadn’t hit a home run in 49 at-bats since the regular season and felt the pressure as the Mets drove traffic onto the bases, but couldn’t hit the big home run to drive those runners in.

Alonso, the team’s best power hitter who leads the NL with 226 homers since joining as a rookie in 2019, was feeling the pressure. If he can’t throw someone over the wall, no one will.

In the ninth inning, with the Mets down 2-0, the Brewers called on closer Devin Williams to close the gates. First, he gave a leadoff walk to Francisco Lindor, who had the Mets’ hits in the game at the time.

“All I kept telling myself was, ‘You have to win this shot.’ No matter what happens, just win that shot and let the guys behind you do the job,” Lindor said of his shot after the game.

After Lindor’s walk, Williams gave up a one-out single to Brandon Nimmo, sending runners to the corners.

Then Alonso went to the front and had the opportunity to rehabilitate himself. After increasing the count to 3-1, he made a substitution in the middle of the plate.

“As soon as I hit it, I was like, ‘Hell yeah! Nobody catches that,” said an enthusiastic Alonso after the game. “I’m so happy right now.”

The spectators weren’t sure whether the ball would go out. Even Lindor had his doubts.

“I went back to tagging,” Lindor emphasized.

The ball came off Alonso’s bat more like a line drive than a moon shot, and it just kept flying until it finally cleared the wall in right-center by 2 to 3 feet, giving the Mets a 3-2 lead. According to Statcast, that’s a home run in just 13 of 30 big league ballparks.

As Alonso ran the bases, he clenched his fist in joy. He had waited so long to deliver this hit, and on the biggest stage he did it.

“When it comes to winning baseball, you have to do your part every day,” Alonso said. “You have to stay focused, you have to stay in control and I continued to do professional attacks. I’m just really happy that I was able to do my part.”

The Mets added another run after Alonso’s home run and won 4-2. They face the Phillies in the NLDS on Saturday.