After James Paxton gave the Yankees six strong innings on Friday night, Aaron Boone turned the game over to his bullpen.

And it was Zack Britton who saved the 4-1 victory, even if Aroldis Chapman closed it.

Getting the final nine outs of Game 5 of the ALCS against Houston never figured to be easy, but it became that much more challenging given the fact Chad Green was used in Game 4 and Adam Ottavino has lost effectiveness.

So to open the seventh, Boone went to Tommy Kahnle, who had pitched well in the postseason and moved ahead of Ottavino in the bullpen hierarchy.

But Kahnle immediately found trouble by giving up a one-out single to George Springer and a four-pitch walk to Jose Altuve.

Any hopes Boone had of getting an inning each from Kahnle, Britton and Chapman were gone, as Boone went to Britton to deal with the lefty-swinging Michael Brantley.

Britton got a grounder to first, but the Yankees were slow to turn the potential double play, so Brantley reached first and Springer moved to third.

Britton preserved the three-run lead when Alex Bregman lined out to center.

“I wanted to keep that offense from getting on a roll,’’ Britton said. “I always look back on my experience closing games. I was pretty comfortable out there and got a little bit sharper as I went on.’’

Britton then went back out, with Chapman warming in the bullpen, and cruised through the top of the eighth, getting a slow grounder from Yuli Gurriel that Gio Urshela made a fine play on at third to open the inning.

Britton followed that by striking out Carlos Correa and Yordan Alvarez to end the inning, allowing Chapman to pitch only the ninth.

“It lined up perfectly,’’ Britton said. “We were ready to go an inning-plus.”

Chapman had appeared in just three games in the postseason, which meant he had pitched just three times in the previous two weeks, including a five-out save to close out the Twins in the ALDS.

He finished the Astros with a perfect ninth for the save, sending the series back to Houston.