He was the best power hitter in the majors in the first three weeks of the season, but the Braves’ Justin Upton had been a shell of his former self for two-and-a-half months since.

The past two nights in Miami, he served notice. The power stroke was dormant, not dead.

Upton hit two doubles and a long home run Tuesday to lead the Braves in a 6-4 win against Miami at Marlins Park, their 12th win in 14 games at the retractable-roof stadium that opened last season. His brother, B.J. Upton, also had two hits and a sacrifice fly.

“It’s good, man,” Justin Upton said of the siblings’ contributions. “As the season progresses, it’s been different guys at different points. You’ve just got to kind of ride it till you’re clicking on all cylinders. It’s nice to have us both swing the bat well tonight.”

Justin Upton had two doubles and three RBIs in the 14-inning series opener Monday, including the tie-breaking double that keyed the Braves’ six-run final inning in a 7-1 win.

He topped that by collecting three extra-base hits in his first four at-bats Tuesday, including a towering leadoff homer in the seventh inning that pushed the lead to 6-4. It was his 16th homer, but only his second in his past 44 games.

“If you see any hitter start to hit the ball hard the other way, they’re very close (to getting hot),” B.J. Upton said. “He’s been doing that lately. He’s definitely cleaned some things up, and he’s trying to keep it simple.”

Julio Teheran (7-4) overcame shaky defense early and worked 7-1/3 strong innings, allowing seven hits and two walks with three strikeouts. Because of a second-inning error by third baseman Chris Johnson, only one of four runs charged to Teheran was earned.

Craig Kimbrel struck out two in a perfect ninth inning for his 24th save.

Brian McCann added two RBIs for the Braves, who moved their lead back to six games over the second-place Nationals. But the most encouraging development for the Braves had to be the Uptons’ performance.

Justin Upton hit .302 with 12 home runs and a .779 slugging percentage in his first 23 games through April 27. Then he hit .220 with three homers and a .305 slugging percentage in his next 60 games through Sunday.

“It’s a long season,” said manager Fredi Gonzalez, whose Braves improved to 3-2 on the six-game trip. “I know we’re always looking for more, but there’s going to be some ups and downs, and you’ve got to be patient with the guys. They’ll be fine. He (Justin Upton) is starting to swing it like he did early in the season, and you see other guys starting to have good at-bats. Maybe not getting a hit in the boxscore, but hitting the ball hard. Those are good signs.”