MILWAUKEE -- Within minutes of National League Wild Card Series Game 3 ending, those Mets fans in attendance at American Family Field -- and there were plenty of them -- had begun to drown out the noise from everyone else. They chanted “M-V-P!” at Francisco Lindor. They shouted “O-M-G!” at Jose Iglesias. And of course they sang “Pete Al-on-so!” over and over and over again.

When Alonso finally emerged from an infield dogpile into clear view, the noise crescendoed. Alonso looked up at them, sprinted to the dugout rail, leaped onto it and raised his fist.

The Mets had just completed, as president of baseball operations David Stearns described it, “one of the greatest games in Mets history” -- a 4-2 win over the Brewers that they snatched from the clutches of defeat. And it was one of Alonso’s own making. Down to the final two outs of the season, in what could have been the final at-bat of his Mets career, Alonso hit a go-ahead, three-run homer to turn a likely Mets loss into further evidence that this team has something special in its bones. Something different.

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Standing in the postgame clubhouse, his eyes red with emotion or the sting of alcohol or some combination of the two, Alonso struggled to find the words to describe what it all meant to him.

“You go through those scenarios as a little kid,” Alonso said, his left hand clutching both a beer and a bottle of champagne. “It’s like, ‘All right, you’re in the playoffs, you’re down by two runs.’ I don’t know. Words can’t explain it.”

All evening, the Mets had struggled to do much of anything against Tobias Myers or any other pitcher the Brewers trotted out of their bullpen. Entering the ninth, everyone other than Lindor was a combined 0-for-24. It was, in many ways, the same old Mets. From 2016 through the eighth inning Thursday, their hitters went 7-for-85 (.082) in winner-take-all playoff games.

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But on this occasion, the Mets weren’t yet eliminated. Facing multi-time All-Star closer Devin Williams, Lindor worked a leadoff walk. Two batters later, Brandon Nimmo singled to put runners on the corners with one out, bringing up Alonso.

For weeks, the Mets first baseman had slumped. He was 0-for-3 on the night and 5-for-41 with just five singles and one RBI since Sept. 19. An inning earlier, he had dropped a foul popup to extend an at-bat. If this was indeed going to be the final game of Alonso’s Mets career, it appeared he was heading out with a whimper.

“No one knows until they go through it what that struggle is like,” was how Nimmo described the situation. “The weight of emotions on him that’s probably been building up on him over the last three weeks or so, and the release of that when you finally come through -- and you come through in a gigantic way for your team -- it’s hard to even put that into words.”

How Alonso came through was as impactful as the mere fact that he did. This was Ron Swoboda making a diving catch in 1969. This was Mookie Wilson grounding a ball down the first-base line in 1986. This was a game the Mets had lost. This was hope smashed into pieces, then sewn back together again.

Facing Williams, Alonso took a strike and three balls without moving his bat. Then, on a 3-1 count, he watched a changeup -- a pitch so devastating that Williams’ version of it has its own nickname, The Airbender -- float toward the outer edge of the strike zone.

“It could have been better,” Williams said, “but it wasn’t the worst pitch I’ve ever thrown.”

Alonso jumped at it all the same, powering it just over the right-field fence. He pumped his fist and screamed, then did it again. His teammates spilled out of the dugout to meet him at home plate, where he became the first player in MLB history to hit a go-ahead homer while trailing in the ninth inning or later of a winner-take-all postseason game.

“I’m so proud of Pete,” said starting pitcher Jose Quintana. “He did it at the right time. The perfect time.”

While no one knows how this Mets season will end, the club has already exceeded expectations to such an extent that at this point, truly, anything seems possible. Every team that has ever beaten the Brewers in the postseason -- all nine of them, over more than four decades -- has at least gone on to win the pennant. Of course, the Mets aren’t thinking that large quite yet. They’ll start with NLDS Game 1 against old friend Zack Wheeler and the Phillies on Saturday. Yet they know they have something special brewing.

Before Thursday’s game, Iglesias kept peppering Alonso with positivity, telling him over and over again that he was “one swing away” from busting out of his slump. Midway through the game, hitting coach Eric Chavez turned to Nimmo and said the exact same thing about Alonso: “One swing away.”

“And sure enough, he was one swing away at the end there,” Nimmo said. “And it came at the biggest time and the most important time that we needed it.

“You never know why things happen. I’m a big believer in things happening for a reason. You just never know why. But this elation that he’s feeling right now, I’m sure he’s never going to forget it.”