The last time before Sunday that Jazz Chisholm Jr. swung Aaron Judge’s bat in a regular-season game, he strained his oblique.

Then he used it again this spring and said he “almost ripped my oblique” again because he swung it as hard as he does with his own lighter bat.

So after striking out in each of his first three at-bats Sunday, Chisholm found the injured Judge’s bat bag, picked one out and brought it to the plate with him in the eighth inning.

Red Sox lefty reliever Joe La Sorsa threw him a first-pitch sinker on the inside edge and Chisholm, not wanting to hurt himself, got off an in-control swing that resulted in a three-run home run that put the Yankees’ 6-1 win on ice.

“I feel like when I pick up his bat, I know I can’t swing as hard as I can, or else I’ll tear an oblique like last year,” Chisholm said. “But I feel like it just helps me to go out there and control the barrel and just try to touch the ball instead of trying to hit it so hard.

Jazz Chisholm Jr. hits a home run during the Yankees’ June 7 win. Robert Sabo for the NY Post

“I was swinging and missing when I thought I was hitting the ball [earlier in the game], so I was just seeing if the bat would change [things]. Sometimes you need a little bit more weight and a little bit less on your swing.”

For those keeping score at home, Chisholm was wearing Giancarlo Stanton’s pants (a slump-busting trick that worked earlier in the season and has stuck) and swinging Judge’s bat — at a time when the Yankees are missing both sluggers to the injured list — to cap the five-run rally in the eighth.

At this rate, Chisholm’s teammates might start offering him any of their belongings if it is going to lead to this.

Aaron Judge watches from the dugout during the Yankees’ June 7 win. Corey Sipkin for the NY POST

“I like when he does that,” manager Aaron Boone said with a grin.

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Chisholm said he had used Judge’s bat one other time, in his second game as a Yankee, and hit a home run.

Judge’s bat is 35 inches and about 33 ¹/₂ ounces, according to Chisholm, whose own bat is 34 inches and 31 ounces.

The second baseman has also used José Caballero’s bat for some key hits this season, and said he has probably used just about every teammate’s bat at least once, except for Paul Goldschmidt and Stanton, as the veterans have bigger bats that were grandfathered in to the current regulations.

“With Cabby’s bat, I think I can still try to muscle up a little bit and be super strong through the zone like I was in the first three at-bats today,” Chisholm said. “But after that, picking up Cap’s bat, I can’t do it. I really just can’t.”