Atlanta's Freddie Freeman, left, shows appreciation Tuesday night Evan Gattis' ninth-inning, two-out solo home run that tied the game. On Wednesday, Gattis hit a grand slam to help Atlanta sweep the Twins.

Atlanta's Freddie Freeman, left, shows appreciation Tuesday night Evan Gattis' ninth-inning, two-out solo home run that tied the game. On Wednesday, Gattis hit a grand slam to help Atlanta sweep the Twins.

ATLANTA — Evan Gattis sent Tuesday night’s game into extra innings with a two-out pinch-homer in the ninth inning.

On Wednesday, Atlanta’s improbable rookie slugger made sure that no late-game dramatics would be needed.

Gattis blasted his first career grand slam in the fourth inning — opposite field, no less — to give the Braves a big early lead on Vance Worley, and they extended their winning streak to six games with an 8-3 interleague victory against the reeling Minnesota Twins.

“He’s a legend,” Braves manager Fredi Gonzalez said of his 26-year-old rookie. “Good for him. The players love him.”

Paul Maholm allowed just one unearned run in 7 1/3 innings, and Ramiro Pena and B.J. Upton also homered. But the story — again — was Gattis, who went through rehab and lived out of his van for several years before returning to baseball after a four-year absence following high school.

Gattis picked on a 3-0 fastball from Worley and hit a towering opposite-field drive into the lower right-field seats near the foul pole. It was his 10th homer of the season, which is amazing considering he’s not an every day starter, and gave him 27 RBI — both totals leading all major league rookies.

“I was a little surprised not to get the take sign. I was lucky to get just enough of it to get it out,” Gattis said. “It felt good.”

Gattis was mobbed by his teammates in the dugout, all of whom had looks on their face as if to say, “Is this really happening?”

“It’s a little weird,” Gattis said. “I’m not used to that yet.”

If the Twins didn’t know about Gattis before this series, they do now.

“He’s a monster,” manager Ron Gardenhire said. “That was impressive.”

Gattis, however, refused to accept the credit for his brilliant play early in his career — or even most of it.

“I love this team,” Gattis said. “All of our pitchers, relievers, everybody in the whole lineup, we all contribute, we’ve all got roles, we’ve all got things we do to help this team. It’s a good feeling right now in the clubhouse. We’re playing good baseball.”

The same can’t be said for Worley, who was acquired form Philadelphia in the offseason to be the Twins’ ace. After the game, the Twins’ opening-day starter was sent down to Class AAA Rochester. His record fell to 1-5 and his ERA rose to 7.21.

“We’re searching for the guy we got in the trade,” Gardenhire said. “We’re counting on him.”

Worley knows he’s been awful.

“My ERA is killing me. They haven’t seen what I can do. I haven’t been consistent whatsoever. I’ll figure it out down there,” he said.

Given an eight-run cushion, Maholm (6-4) coasted, giving up only the unearned run in the sixth inning. He allowed seven hits, walked one and struck out four, throwing 112 pitches.

The series sweep was the second straight for the National League East-leading Braves (28-18) and extended the losing streak by the Twins (18-25) to eight games.

Tuesday night’s rain-delayed, 10-inning game didn’t end until 11:51 p.m., leaving the teams barely 12 hours before the 12:10 p.m. start for the series finale. But Braves’ hitters looked well-rested as they rode the momentum of the 5-4 victory set up by Gattis’ homer.

The Braves had a first-inning run before Worley could get an out, added two runs in the third and then broke the game open in a five-run fourth, chasing the Twins’ right-hander.

Pena hit a hanging curveball just into the right-field seats for his second homer of the season in the third, and Upton connected on a 3-2 fastball for his fourth homer to start the knockout fourth.

Gattis, given the 3-0 green light, turned the game into a rout after Worley had loaded the bases by giving up two singles and a walk. It was his third homer in five plate appearances, the first two blasts coming as a pinch hitter.

Gattis’ start behind the plate was his first since May 5 — the day before Brian McCann returned from the disabled list. But he had started six games since in left field and had thrived as a pinch hitter. On Saturday, Gattis hit a decisive two-run homer in the eighth inning against the Los Angeles Dodgers.

Worley, meanwhile, is struggling as much as Gattis is thriving. He allowed 10 hits, walked two and hit two batters in 3 2/3 innings.

Cory Rasmus, making his major-league debut, finished for the Braves and allowed ninth-inning homers to Twins rookies Aaron Hicks and Oswaldo Arcia. It was the fourth homer of the season for each.

The Braves are off today, while the Twins continue their road trip with the opener of a four-game series at Detroit.

NOTES: Twins 3B Trevor Plouffe was placed on the seven-day disabled list with concussion symptoms after having to leave Tuesday night’s game against the Braves in the 10th inning after being kneed in the head by Braves 2B Dan Uggla while trying to break up a double play. … RF Chris Colabello, 29, was 0 for 4 in his major league debut after being promoted by the Twins from Class AAA Rochester, where he was leading the International League with 12 homers and batting .358.