NEW YORK -- Brett Gardner, welcome back.

Hours after New York Yankees manager Aaron Boone stood up for his struggling 34-year-old leadoff man, saying he wasn't entertaining the possibility of moving Gardner down in the batting order, the veteran went out and had his best game of the season Wednesday night.

In sparking a 9-6 win over the rival Boston Red Sox that gave the Yankees sole possession of first place in the AL East, Gardner was New York's extra-base hero.

Although his doubles in the first and third innings led to a couple of early runs, it was his triple in the eighth that keyed yet another Yankees comeback by bringing home the tying and go-ahead runs.

"Before the game we talked about, we feel like he's been a little bit unlucky," Boone said, referencing the .198 batting average Gardner brought into play. "[Wednesday], he was really able to get in some good counts and put some aggressive swings in the strike zone and drive some balls. That last one [the triple], obviously, he really stepped on that one the other way."

The opposite-field drive that landed deep into the left-center gap, just in front of the 399-foot sign, brought home Neil Walker and Gleyber Torres. Walker began the eighth inning with a leadoff double to left, continuing to come through with timely, clutch at-bats.

Walker said it's "happenstance" that he continues to find himself at the plate in key situations. On Tuesday, Walker's pinch-hit double in the seventh led to the go-ahead run in a 3-2 Yankees win. A ninth-inning double by Walker on Sunday helped set up Torres' walk-off homer in that comeback. Four days earlier, his ninth-inning leadoff walk kicked off another rally that ended in a Yankees win.

"You love seeing him come up there in those situations, whether it's a lot of the key walks he's worked, or lately a couple of extra-base hits," Boone said.

Added Walker: "[The mindset] is go up there, try to have a good at-bat and find a way to get on base."

Following Walker's eighth-inning double Wednesday, third baseman Miguel Andujar immediately moved him over to third, chopping a ball to the right side of the infield. One batter later, the rookie Torres drew a five-pitch walk. That led Red Sox manager Alex Cora to bring in closer Craig Kimbrel to face Gardner.

Although Gardner had been struggling to get hits much of the season, he was putting together the types of swings and at-bats that gave the Yankees hope. Boone said before the game that various data from the team's analytics department showed the outfielder was making adequate contact and was demonstrating a careful eye.

He just hadn't really been able to buy any hits, causing some to wonder whether the Yankees should tweak their lineup. Boone adamantly said he still considered Gardner his leadoff hitter.

"Any time you look up at the board and you're hitting .200, but maybe you see some numbers that suggest maybe you should be hitting a little better or otherwise," Gardner said. "Up there at the plate, I haven't felt completely lost. I've been feeling good physically. I've been seeing the ball well. And my work's been pretty good in the cage and batting practice. The results just haven't been there in the games.

"So when that's the case, you just have to keep working, try not to overthink it and keep things simple."

Wednesday marked the first time this season that Gardner had multiple extra-base hits in a game. It was his fifth career game with three extra-base hits, and his first since last May.

In the eighth, when Gardner was racing around second and headed for third with no plan to stop, Torres picked up the pace of his own sprint around third, realizing there was no going back. One night after getting thrown out at home by several steps, Torres was being pushed by the speedy leadoff man.

Torres scored, giving the Yankees the lead for good.

One batter later, Gardner touched the plate too, after Aaron Judge gave the Yankees a little insurance with a monstrous 429-foot two-run homer to center field that sent the Bronx faithful into a frenzy. The energy within Yankee Stadium was reminiscent of the sights and sounds from postseason classics of the past.

The come-from-behind win was the Yankees' fifth this season when trailing in the eighth inning.

"You can feel the electricity in that building in that inning, and for guys to completely go up there and control the moment," Boone said. "I just love the way our guys compete in the toughest of moments, when there's a lot on the line, when it's loud and when there's excitement. They really lock in and their concentration is extra focused."