Feeling flirty, the still-filling in Citi Field crowd offered Blue Jays star Vladimir Guerrero Jr. a hearty round of applause during pregame introductions Friday afternoon, a reminder of his status as a pending free agent and the Mets’ status as a big-market team that is acting and spending like it.

After that, though, it was all about these Mets in a 5-0 win over Toronto.

How will they follow a charmed 2024 season? To start, with a charmed home opener, a practically perfect day at the ballpark featuring a little bit of everything: homecoming king Pete Alonso homering in his first at-bat, Juan Soto receiving a standing ovation in the first inning and collecting his first Queens hit in the sixth, Tylor Megill pitching well into the sixth, and three relievers combining for 3 2/3 scoreless innings.

Even the weather — after rain had been forecast for much of the week — held up just fine, making for a dry, comfortable experience for the sold-out audience of an announced 43,945. That was larger than all but one home crowd last year.

The game-sealing sequence came in the bottom of the fifth and top of the sixth. After Reed Garrett inherited from Megill a two-on, one-out jam, he struck out former Mets infielder Andres Gimenez and Alejandro Kirk — both swinging at splitters — to escape. In the next half-inning, the Mets all but put the game away with a three-run rally highlighted by run-scoring doubles from Soto and Brandon Nimmo.

The biggest hit of the day, though, came from Alonso. Playing in his first home game since agreeing to return to the Mets in early February, ending months of wondering whether he would move on from the only professional organization he has ever known, Alonso rose to the moment again — just as he did last October in Milwaukee and in recent days in Miami (twice).

Down in the count 1-and-2, Alonso got a fastball from Kevin Gausman (5 1/3 innings, three runs) low and actually off the plate. He flicked it over the rightfield wall. Upon returning to the dugout, with fans chanting his name, Alonso popped back out for the curtain call, tipping his helmet and raising both arms, with a smile.

Megill made it through 5 1/3 scoreless innings with minimal stress. He limited the Jays to two hits and three walks, with two of those coming to his last two batters. That was when Carlos Mendoza, not wanting to risk what at that point was just a 2-0 lead, yanked him in favor of Garrett.

With the win, the Mets improved to a winning record (4-3) for the first time on the young season.