PHILADELPHIA -- All told, the Mets spent 90 days atop the NL East, their longest such stretch since 2007. But as they learned that season, first place only matters if they occupy it on the final day of the season.

In that regard, New York has plenty of work to do.

The Mets’ 4-2 loss to the Phillies at Citizens Bank Park on Friday knocked them out of the division’s top spot for the first time since the morning of May 8, when they woke up a game back of Philadelphia in the NL East. What’s more, the Braves won as well, meaning the Mets are at risk of falling as low as third place on Saturday if they lose again.

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“I know you guys are expecting to hear some answer, but there’s nothing,” starting pitcher Marcus Stroman said. “Nothing’s different. We’re just in a little bit of a rut, hoping to continue to keep the same confidence and come out of it.”

The Mets have now lost five of their last six games and seven of their last nine, transforming a four-game lead into a half-game deficit in less than a week. Their mathematical odds to make the postseason, according to FanGraphs projections, have fallen from 77.9 percent on July 28 to 43.0 percent on Friday morning.

Those odds will be lower still when the Mets wake up on Saturday, still nursing the wounds of another game in which they struggled to hit. Facing one of the Phillies’ top Trade Deadline acquisitions, Kyle Gibson, the Mets plated their first run on Dominic Smith’s RBI single in the third inning. But they did not score again until Jonathan Villar’s solo homer in the ninth despite loading the bases with no outs in the fourth. They stranded eight men on base in total.

Stroman delivered five innings of two-run ball, becoming the 15th consecutive Mets starter to fail to record a win. Any designs on a comeback later evaporated when Bryce Harper hit a two-run homer off Edwin Díaz in the eighth, though by that point, the ballpark’s energy had long since shifted fully toward the home team. While the Mets appeared listless due to another poor offensive performance, the Phillies punctuated their own strong play with a series of screams, yells and fist pumps -- none bigger than Hector Neris’ after retiring the side in the seventh.

When Harper struck his Statcast-projected 442-foot blast in the eighth, he stared it down for several moments while Díaz pointed to the sky, apparently believing it to be a routine flyout.

It wasn’t. In recent weeks, little besides losing has been routine for the Mets, who have done it with more regularity than all but seven teams in the Majors -- none of them in realistic contention for a playoff spot. The Mets are, and they now must try to engineer a different path to October.

“It’s not fun,” outfielder Brandon Nimmo said. “We’re all competitors. We all want to win. We know this is a big series. We know the last series was a big series. We’re not going out there trying to lose, so it sucks. It’s not fun at all. But after that 30 minutes to an hour after the game goes by, and you can start to reassess, that’s when people start lifting each other up and encouraging each other for tomorrow.”

For weeks, the Mets had relied on the notion that despite everything that had gone wrong for them -- injuries, inconsistencies and more -- they managed to hold onto first place through it all. They can’t rely on that anymore.

Instead, they must continue to play out their schedule and hope that something changes, all while trying not to overreact to a few bad weeks.

“It’s not great, because we acknowledge that we’ve been in first place for so long, and we would have loved to have kept it for the whole season,” Nimmo said. “But the Phillies are on a good streak right now, and not so great for us. That’s the way things have worked out, and now we’ll just have to try to recapture it.”