NEW YORK — The last time the New York Yankees saw Walker Buehler in relief in the Bronx, they were doomed. He was there to punctuate their self-inflicted humiliation in the final game of the World Series last fall, and the Yankees capitulated, 1-2-3, season over.

On Sunday, Buehler’s presence meant that things were going well, at last, for the Yankees. Demoted to the bullpen by the Boston Red Sox this weekend, Buehler came in with a deficit. Last October, his curveball clinched the title for the Los Angeles Dodgers. This time, a Buehler curveball wound up in the right-field seats as Jazz Chisholm Jr.’s second home run.

The Yankees never trailed in Carlos Rodón’s 7-2 victory, their only win in this four-game showcase series. Their leadoff hitters blitzed Boston starter Dustin May in every inning — walk, single, homer, double, homer — and the Yankees played crisply all around.

“We have played a lot of those games, believe it or not,” Yankees manager Aaron Boone said, citing the defense at several spots. “So, yes, always good to play a clean brand of baseball, especially when you’ve had a tough weekend and you’ve lost three to your rivals, to come out and kind of do it in all facets — Carlos set the tone, defense, power, adding on, getting the guy over, sacrifice fly. It was good to see all that.”

The Yankees (70-60) and Red Sox (71-60) are separated by a half-game with five weeks to go in the regular season. With the Toronto Blue Jays five games ahead in the American League East, the pennant race, such as it is, will mostly settle seeding for the wild-card round in all likelihood. Only one team outside the current AL playoff mix (the Kansas City Royals) even has a winning record.

It is easy to lose perspective when so much bad baseball scrambles the signals. It is all part of the experience in New York.

“The highs are so much higher, the lows are so much lower,” said third baseman Ryan McMahon, who was traded to the Yankees last month from the worst team in the majors, the Colorado Rockies. “But honestly, man, these guys do a really good job of showing up ready to go every single day. Even like — we got punched in the mouth a little bit, right? We weren’t playing great, but we showed up ready today.

“I felt like we showed up ready all those other days, too. And it sucks (to lose), but it’s the old cliche — it’s baseball, stuff like that’s gonna happen.”

Trent Grisham admires his fifth-inning home run. He also homered to lead off the third. (Vincent Carchietta / Getty Images)

The Yankees’ flawed fundamentals may cost them in the end, as they did in last year’s World Series. But they are strong enough to win slugfests (Trent Grisham also homered twice on Sunday) and power over most mistakes. They lead the majors in homers and trail only the Dodgers in runs per game. They’ll have a chance in October.

Sunday’s victory snapped the Yankees’ eight-game losing streak against the Red Sox. In both of their last two series, the Yankees were coming off a night game in a different city, while the Red Sox were off. That’s no excuse — that’s life in the big city, you could say — but you’d rather be well-rested than exhausted. In any case, this was their first eight-game losing streak to the Red Sox since … 2009, a year that turned out just fine.

This week gives the Yankees a chance to pad their record, with seven games against the lowly Washington Nationals and Chicago White Sox. The Yankees then play four series against contenders — Houston, Toronto, Detroit, Boston — and finish with four against also-rans: Minnesota and Baltimore on the road, the White Sox and Orioles at home.

Then it’s on to October, and they’ll take their chances. More games like Sunday’s will be critical, especially in the field. McMahon made a smooth backhand to start a double play with Chisholm in the fifth, and with two on and two out in the ninth, first baseman Paul Goldschmidt scooped McMahon’s one-hop throw from the hole to end it.

“We played a good, clean game tonight,” McMahon said. “I think if we do that on defense, we’re never going to be out of the game. Because of those weapons up and down the lineup, we’re always going to have a chance if we take care of the ball. That’s my personal opinion, and I think we do have the guys to do it.”

Ryan McMahon reacts after making a play in the series opener. “We played a good, clean game tonight,” he said of Sunday’s 7-2 win. (Wendell Cruz / Imagn Images)

The Yankees have bailed on some of those guys along the way, eating the sunk costs on underperforming veterans like DJ LeMahieu and Marcus Stroman. Then again, they’ve shown extraordinary faith in shortstop Anthony Volpe, the only qualified hitter in the majors with a sub-.700 OPS and a batting average below .210.

From June 30 through July 30, Volpe played every game and drew one walk. He recently homered seven times in two weeks — nobody doubts his raw skills — but Volpe’s overall struggles, at the plate and in the field, have cried out for a change.

Boone gave in on Sunday, using Jose Caballero at shortstop for just the second time since July 31, when the Yankees acquired him in a trade with the Tampa Bay Rays. Boone continued to portray Volpe, 24, as impervious to the booing of his hometown fans.

“(He’s) mentally very tough and totally wired to handle all the things that go with being a big leaguer in this city,” Boone said, “and a young big leaguer that’s got a lot of expectations on him.”

With a three-run lead in the eighth inning on Sunday, Boone shifted Caballero to right and inserted Volpe at shortstop. The first batter dutifully hit the ball his way — that’s baseball, Suzyn — and Volpe made the play. It started a perfect inning for the mercurial Devin Williams, who has retired the side in order in five of his last seven games.

“Really good to see him just continuing to pitch really well around a lot of things that have gone on this year,” Boone said. “That’s a credit to him and the quality of pitcher he is and the fortitude to just keep going. Because certainly that’s what he’s capable of.”

The Yankees are capable of games like Sunday’s. They are 40-41 in their last 81 games — half a schedule of mediocrity — so it’s hard to trust that they’ll turn hot enough to play that way consistently when it matters most. But it is possible. And it would be fairly shocking if they don’t at least get the chance.

(Top photo of Aaron Judge and Jazz Chisholm Jr.: Vincent Carchietta / Getty Images)