MINNEAPOLIS -- When the Braves tied Monday's game in the seventh inning, Miguel Sanó turned to assistant hitting coach Rudy Hernandez in the batting cage nestled behind the first-base dugout, where he had been working for most of the game on hitting breaking balls off a pitching machine.

“If nobody does anything, I'm going to take care of it,” Sano told him.

Sano walked into the dugout in the ninth inning and sat with Willians Astudillo, Nelson Cruz and club interpreter Elvis Martinez at the end of the Twins’ bench before he stepped up to the plate as a pinch-hitter. He had one thought on his mind: “One swing, and come back to the dugout.”

He didn’t miss.

That one swing connected so soundly that Atlanta center fielder Ronald Acuna Jr. started jogging towards the Braves’ dugout long before the ball careened off the limestone facing of the second deck above the center-field batter’s eye and sealed the Twins’ 5-3 walk-off win over the Braves in Monday night’s battle of division leaders at Target Field.

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“When you've got something in your heart and you feel it, that's one of the biggest things,” Sano said.

The homer traveled an estimated 443 feet off Sano’s bat and was the Twins’ first pinch-hit, walk-off homer since Michael Cuddyer walked off the Angels on April 19, 2006. And rather surprisingly for a season chock-full of long balls by a lineup destined for the record books, Sano’s bomb was the Twins’ first walk-off shot of the year and the first of his career.

The Twins are now the fourth team to reach 70 wins this season, joining the Dodgers, Yankees and Astros.

“We’re playing against good teams that are going to be probably playing for a long time into the fall,” manager Rocco Baldelli said. “I think when we play against these teams, we step up to the plate and we take our game to a different level and we play well. I’ve been very impressed with the way our guys have competed against all these teams that have shown up here, and we expect nothing less of ourselves.”

Atlanta had erased a two-run deficit in the seventh inning before reliever Trevor May touched 100 mph in two scoreless innings to hand the game over to his offense in the bottom of the ninth, with the game tied, 3-3.

After rookie Luis Arraez poked a two-out single to left off Braves reliever Chris Martin as part of his third straight multi-hit game, Baldelli had an enviable array of sluggers on his bench that he could have chosen to pinch-hit for Ehire Adrianza.

Given that the Twins were facing notoriously homer-averse Braves right-hander Mike Soroka, who has also been markedly more effective against right-handed hitters this season, four right-handed power bats -- C.J. Cron, Mitch Garver, Jonathan Schoop and Sano -- were out of the starting lineup and available to the Twins’ skipper.

Baldelli put his trust in the game-changing power of Sano, who went through a brutal slump in June but has been seeing the ball much better in the last several weeks.

“Especially with a man on first base more than anything else, I think it made sense to send a guy up there that has a chance to really impact the ball and maybe do something like he did,” Baldelli said. “Sometimes it changes when you talk about a guy maybe being in scoring position, you might look to somebody else in a different situation. You never know.”

After taking a slider for strike one, Sano got a cutter from Martin that caught too much of the outside corner. After his swing, he flung his bat aside, raised both his arms towards his dugout as his teammates came pouring out, and started the long trot around the bases.

"I just didn’t execute the pitch,” Martin said. “That was supposed to be off the plate, get him leaning out a little bit and then go from there. Obviously, you saw what happened. I left it out over the plate and he’s got long arms. He’s got leverage. I attack him the same way every time and I think he finally figured it out.”

Sano appears to have figured out a lot of things since his late start to the season due to his injury and a slump through which Baldelli’s faith in the slugger did not waver. He made some changes to his swing mechanics on the fly and continued to work on hitting off the machine -- and he’s hit .292/.390/.651 with 10 homers since June 28 as a result.

Monday night’s heroics were just another example of that progress.

“I’m proud as hell of that guy,” May said. “We could talk all day about where he’s come just this year. … He knew exactly what he needed to do to win the game there. He got his pitch, and put a nice easy swing on it.

“It’s just evident all the things he’s been working on in the cage and how hard he’s been working on making the best of those opportunities and just doing everything he can to get the job done.”