The excitement Neil Walker provided with a majestic home run was slowly oozing into the late summer night air that had replaced a hard afternoon rain, which turned a Red Sox-Yankees matinee into a night game on Tuesday.

Walker rewarded Aaron Boone’s move to start the switch hitter at first base over Greg Bird and Luke Voit against Red Sox right-hander Nathan Eovaldi with a colossal three-run homer in the seventh inning that gave the Yankees a two-run lead entering the ninth.

Yet, by the time second baseman Gleyber Torres and Zach Britton, who got the call to the bullpen ahead of Dellin Betances, committed ninth-inning errors that led to a run, the excitement had dissipated and a sense of dread smothered Yankee Stadium.

After Britton threw away a double-play ball that would have ended the game at second, he got another chance and didn’t flush it. Britton fielded Ian Kinsler’s comebacker, fired to Torres at second and his throw to first completed a double play that gave the Yankees a pulsating 3-2 victory in front of a Yankee Stadium crowd of 38,695.

“A little frustration, but also knowing the way Zach was throwing the ball we were going to get another opportunity at it,’’ Boone said. “[Pitching coach] Larry [Rothschild] said [to Britton], ‘You are getting another [ground ball] here and he stepped through with confidence and we were able to get it done.’’

Aaron Judge returned to the starting lineup for the first time since fracturing his right wrist July 26 and went 0-for-4 despite hitting two balls hard and lofting a fly ball to the warning track in right.

The victory kept the Yankees from losing ground to the A’s, who dropped to two games back pending their result against the Angels in Oakland late Tuesday night, in the chase for the top wild-card spot that has home field attached to it for the Oct. 3 loser-go-home tilt.

It also denied the Red Sox from celebrating their third consecutive AL East title inside the Yankees’ home. The Red Sox will get a chance to do that by winning one of this week’s remaining two games in The Bronx.

Had it not been for Walker’s clutch homer off right-hander Ryan Brasier after Aaron Hicks and Gary Sanchez each walked, the Red Sox would have been dancing on the field and soaking each other in champagne and beer in the visitor’s clubhouse.

Former Yankee Nathan Eovaldi blanked the Yankees through six innings in which he allowed two hits and fanned five. If the Red Sox have a weakness it’s the bullpen, and that was proven as soon as Eovaldi left the game.

Brandon Workman walked Hicks leading off the seventh and, one out later, Sanchez. Brasier entered and Walker drove a 3-2 pitch into the second deck of seats in right for a 3-1 lead.

“[The count] was 3-1, then 3-2 and he hung a slider and I was able to barrel it up,’’ Walker said of his 10th homer. “It was a long day but to end the game with a win is great.”

J.A. Happ continued to make a strong case he should be Boone’s choice to start the wild-card game by allowing one run and four hits in six innings. Most impressive was the veteran lefty allowing just one run in the third when Kinsler opened with a single and moved to second on a balk. Steve Pearce walked for the second time in three innings and the runners moved to second and third when Sanchez couldn’t handle a fastball to J.D, Martinez that was supposed to be away and cut inside and off the catcher’s glove for his 14th passed ball.

Martinez’s fly to center scored Kinsler, but Eduardo Nunez ended the inning with a routine fly to center.

“Walk worked the count and got a pitch to hit,’’ Happ said. “It was huge for us. We needed it.’’

And almost flushed it.