ete Alonso received among the loudest cheers — if not the loudest —during the Mets’ on-field introductions Friday, and that adulation didn’t stop once the game began. 

A one-man mob this week, the slugging first baseman homered in his first plate appearance and received a curtain call after reaching the dugout to set the tone for a happy home opener in Queens. 

For the first time this season the Mets are above .500, with a 5-0 victory over the Blue Jays in front of a Citi Field sellout of 43,945.

It marked the fifth time in the last six seasons the Mets won a home opener. 

Alonso received a rousing ovation here last year during Game 5 of the NLCS with his future in the organization uncertain as the Mets departed for what became their final game of the year, in Los Angeles. 

Pete Alonso hit a two-run in the first inning of the Mets’ win on Friday in the home opener at Citi Field. Charles Wenzelberg / New York Post

Pete Alonso delivers a curtain call after his first-inning homer. Charles Wenzelberg / New York Post

But the popular first baseman returned on a two-year contract worth $54 million following protracted negotiations, and the fans got to express their gratitude on this day — first with a warm ovation during introductions and then with the curtain call following his first-inning homer. 

After Francisco Lindor doubled leading off, Alonso cleared the right field fence against Kevin Gausman.

It continued a thunderous week for Alonso, who hit a grand slam on Monday and two days later smashed a three-run blast in the eighth inning that led a comeback victory in Miami. 

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The Mets (4-3) got what they needed from Tylor Megill, who fired 5 ¹/₃ scoreless innings in which he allowed two hits and three walks and struck out four.

The right-hander has pitched to a 0.87 ERA over his two starts this season, both Mets victories. 

Megill’s only whiff of trouble early occurred in the second, when he surrendered a two-out triple to George Springer before walking Will Wagner and retiring Ernie Clement for the third out. 

Tylor Megill had a strong start for the Mets. Charles Wenzelberg / New York Post

Megill retired eight straight batters before walking Vladimir Guerrero Jr. and Anthony Santander in succession in the sixth.

Reed Garrett replaced Megill and struck out Andrés Giménez and Alejandro Kirk to escape the inning. 

The Mets scored three runs in the bottom of the inning to open a 5-0 lead. 

Juan Soto delivered an RBI double for his first hit at Citi Field in a Mets uniform as part of the rally.

Juan Soto hit an RBI double for his first Citi Field hit. Charles Wenzelberg / New York Post

Juan Soto celebrates his double. Charles Wenzelberg / New York Post

Brandon Nimmo also stroked an RBI double and Starling Marte’s sacrifice fly brought in the inning’s third run.

Lindor’s walk sparked the inning. Alonso was intentionally walked after Soto’s double. 

A.J. Minter and Max Kranick combined to work the final three innings scoreless.

Reed Garrett got the Mets out of the jam in the middle innings. Charles Wenzelberg / New York Post

The right-hander Kranick pitched the eighth and ninth in a third straight strong performance to start the season.