MIAMI -- Prior to the series opener against the Marlins on Friday night, Francisco Lindor wasn’t sure where the bathroom was in the visiting clubhouse at loanDepot park. Mere hours later, he needed no help finding the wall in center field.

Lindor got the ball rolling -- or, rather, flying -- in the first inning of the Mets’ 5-3 win, squaring up a middle-up 99.1 mph sinker from Marlins ace Sandy Alcantara for a two-out solo homer. Entering Friday, only 11 home runs had been hit off pitches 99.1 mph or above this season, and Lindor’s addition to that elite class marked the first time in his career he’d hit a 99-plus mph pitch over the fence.

“You got a pitcher as good as Alcantara, [a first-inning homer] takes away a little bit of his invincibility,” manager Buck Showalter said.

“Lindor got me tonight,” Alcantara said. “He was aggressive tonight … I was able to throw my best pitch; I think I missed a little bit up in the zone. They hit a spot to hit the ball. … Like I said, just lost the fight tonight. I think [Lindor’s] hot right now.”

Alcantara is right, Lindor is hot -- especially against the Marlins. The New York shortstop entered Friday with a 1.049 OPS (.677 slugging percentage) in his past eight games against Miami. That includes his seven-RBI performance last weekend across the Mets’ four-game series at Citi Field.

And Lindor only added to that torrid stretch on Friday, with a bases-clearing double in the sixth inning after a successful challenge on both outs of a double play loaded the bases with no outs in a tie game (Mark Canha went yard in the top of the fifth inning, his sixth homer of the year).

“[That challenge] changed the momentum for our side for sure,” Lindor said. “[Brandon] Nimmo running the bases did an outstanding job and [Starling] Marte -- that at-bat doesn’t happen without them. … It changed everything.”

Lindor came within mere feet of a grand slam with that sixth-inning double, giving the Mets enough of a lead that Taijuan Walker and the bullpen had room to work in a troublesome bottom of the seventh inning.

Walker maintained his streak of quality outings vs. the Marlins, allowing three runs on eight hits and two walks across six-plus innings. He struck out five batters, including the heart of the Miami order.

“[Our offense], they kept picking me up,” Walker said. “That was a big, huge inning from Francisco, getting the double and three runs in. And I end up getting that shutdown inning [right after], I think just kind of turned the game around right there.”

The numbers prove as much. Lindor’s 56 RBIs rank fourth in the Majors and third in the National League, behind Pete Alonso (66) and the Cardinals’ Paul Goldschmidt (61). The Mets are the only team in the Majors with two players who have 50-plus RBIs. The club now has 134 RBIs with two outs, which is tied with the Braves for most in the Majors.

Lindor had already set the franchise record for most RBIs by a shortstop prior to the All-Star break, and that’s including a 10-game stretch without an RBI earlier this month while healing from breaking the tip of his right middle finger at the beginning of June.

The accolades are further proof of the grind Lindor puts in every day. Even with what he’s said is a fingernail getting ready to fall off, he’s continuing to put in quality at-bats and swing for the fences, which more often than not is resulting in a hit.

“He’s a tough guy,” Showalter said. “I see the popup he hit today almost dropped and he would have been on second base. Those are things that we see again and again … this is a sport that challenges you physically every day.”