lMets pitcher Luis Severino reacts after the sixth inning during Game...

lMets pitcher Luis Severino reacts after the sixth inning during Game 2 of the NLDS against the Phillies at Citizens Bank Park in Philadelphia on Sunday. Credit: Newsday/J. Conrad Williams Jr.

 PHILADELPHIA

The Mets traveled approximately 4,171 miles over two weeks, repeatedly shuttled between two time zones and traded punches with the Phillies for nine innings Sunday to get to the brink of returning to Citi Field with a 2-0 lead in their best-of-five Division Series.

So close. But in October, six outs can be a bridge too far, and the distance finally was too great for the Mets to ultimately power through in a 7-6 loss that they fought like heck to prevent from happening.

Despite a pair of homers by Mark Vientos, the second a tying two-run blast in the top of the ninth, it was the Phillies’ Nick Castellanos who delivered the deciding blow this time.

With two outs in the ninth and Tylor Megill into his second inning of relief — replacing the ineffective Edwin Diaz — Castellanos ripped an RBI single for the walk-off winner that evened the series at 1-1 heading to Flushing for Tuesday’s Game 3.

“It feels horrible. We lost,” Megill said.

Totally understandable. But there was another layer to what happened Sunday night at Citizens Bank Park, where the Mets turned a crowd of 45,679 against its own team — the fans booed their flat-as-pancake Phillies on numerous occasions — before having the game swiped from them in the ninth.

 

The weekend, as a whole, has to be considered a net win for the Mets, who left Flushing on Sept. 22 — after beating the Phillies and Zack Wheeler in that Citi Field finale — then endured one of the more grueling stretches of travel baseball any team could ever experience (one with their own jet, anyway).

To return to Flushing with home-field advantage in this Division Series — and just being back in their homes, period — was a reason for the Mets to manage a smile despite the Phillies’ late gut punch.

“We’ve been on the road for the last six months, it feels like,” said Luis Severino, who shut down the Phillies for five innings and was poised to do so in the sixth before Bryce Harper and Castellanos took him deep back-to-back to wipe out the Mets’ 3-0 lead. “It feels good. We’ve been winning games. So we’re going home, and now the crowd’s going to be into it.”

Upon showing up in Philly, the Mets stunned the NL East champs in Saturday’s Game 1, outlasting Wheeler and then beating two All-Star relievers with a relentless five-run eighth.

On Sunday, the Mets led 3-0, thanks to homers by Vientos and Pete Alonso, and after the Phillies’ sixth-inning volley tied the score, Brandon Nimmo put them in front again with a solo shot in the seventh.

But that advantage lasted only into the eighth, which is when the now officially worrisome Diaz gave up two runs on a walk, Castellanos’ single and a triple by Bryson Stott. The viability of Diaz is the one thing for the Mets to be most concerned about after their two-week trek, but they’ve been able to get this far with his glitchy moments, so maybe their closer can shake off the bad memories by Tuesday.

“Will be good to get back home, sleep in my bed and be ready to go,” Diaz said.

Once the clubhouse door swung open Sunday night, the Mets, for really the first time in the past week, did look tired. Many were slumped at their lockers, almost needing to catch their breath before dressing for the bus ride home. If you felt stressed out and exhausted watching these games from your couch, imagine the toll it must take on the Mets to go all-out to win them.

“I am absolutely drained right now,” Nimmo said. “We would’ve loved to win this game, too ... but sometimes you’re not going to win. We threw some punches and we did a really good job and I’m very proud of these guys. If you would’ve asked before those games if you would’ve taken that, you probably would’ve. You’re not going to win them all.”

Give the Mets credit, because they certainly believe they can. After the Citi Field regular-season finale, the Mets to a man pledged a return to Flushing. It wasn’t a guarantee. More like a gut feeling, a sense of what this team was capable of, and they were confident that October baseball would be in their future.

The past week has been like nothing that came before in the 63-season history of the franchise. How was it possible? That the Mets could simply refuse to lose, by sheer force of will, then come back — after reloading emotionally and mentally — to do it all over again?

I’ve posed that question to numerous Mets during this wild-card road show without getting any tangible explanations. Harrison Bader came the closest.

“We’re actually having the most fun we’ve ever had for being two weeks on the road,” he said. “I think we love it, you know. It’s a traveling circus.”

Now the next stop for that circus is Citi Field, with the Mets having a chance for the first-ever clincher there. They couldn’t be happier about that.