MINNEAPOLIS -- Joey Gallo was looking at an 0-2 count, and he had seen a plenty of sliders from Minnesota Twins left-hander Adalberto Mejia.

In a season that has been built on the promise of long home runs and the frustration of strikeouts and a dwindling batting average, the situation normally would have been lights out for the Texas Rangers' big, young slugger.

Gallo, though, is learning from his mistakes in his longest go-around in the major leagues.

The Texas first baseman stayed on another breaking pitch from Mejia and hit it an estimated 430 feet. His three-run homer provided the cushion, and A.J. Griffin cruised through six innings in his return from the disabled list as the Rangers beat the Twins 4-1 on Thursday to open a four-game series.

"He's getting better every day he goes out there," Texas manager Jeff Banister said of Gallo. "We talked about, prior to the game, how he's now keeping the ball in the middle of the field, driving the ball to center, staying off the pull zone, not as much of a chase. Now, there's still some balls down that he swings at, but he's able to manage the at-bat."

Gallo's 29th homer of the year was another towering shot for the third-year player who has eight homers in his past 13 games. Gallo said he has talked to the veterans on the team, including Adrian Beltre, about improving his two-strike approach.

"Just trying not to go down looking as much as I have been," Gallo said. "At least try to put some kind of bat on the ball. ... Just try to make something happen. If you go down looking, you're leaving that in the umpire's hands. I'd rather leave it in my hands. I know they're going to be cautious with me. That's just what comes with you being a power hitter."

Griffin (5-2) allowed just two hits and a walk, surrendering one run and striking out four batters. Keone Kela and Matt Bush each pitched a scoreless inning in relief, and Alex Claudio finished with his fifth save in six chances.

Mejia (4-5) gave up four runs on seven hits and three walks in four innings.

The Minnesota starter didn't appear long for the outing after walking the first batter he faced, Delino DeShields, and allowing back-to-back hits by Elvis Andrus and Nomar Mazara. Mazara's single to center plated DeShields.

Mejia recovered to strike out the next three batters on his way to five consecutive strikeouts.

"The first inning I couldn't get a grip on the ball," Mejia said through an interpreter of the unusually cool August game with the game-time temperature of 56 degrees. "I think the weather, it was too cold for me and I couldn't grip the ball. My hand was kind of numb. But after that, I was able to get a grip on the ball and things went better."

The Rangers finished off Mejia in the fourth.

Mike Napoli doubled and Carlos Gomez walked before Gallo hit a towering homer to the second deck in right-center field.

"He settled in and did a nice job of minimizing there in the first inning with the strikeouts," Minnesota manager Paul Molitor said of Mejia. "He kind of kicked it into gear there for a couple innings, but the pitch count was climbing, and when he had a chance to finish guys there to keep the game tied, he couldn't make that last pitch."

Gallo has four homers in the past three games. Two of the blasts at home were tracked at 456 feet and 460 feet.

The 23-year-old Gallo is in his first full season in the majors after getting a taste each of the past two years. While participating in the Futures Game at Minnesota's Target Field in 2014, Gallo belted one home run that hit a truck parked in the stadium's right field plaza.

"That's a big man that creates great leverage," Banister said. "He's strong. When you do that in a game, they're very impressive. But any of them that go into the (stands) are nice, doesn't matter where they land."

Griffin was back after missing more than two months with a left intercostal strain. The only blemish on his line came in the third. He walked Robbie Grossman to lead off the inning, and Grossman scored from first on Byron Buxton's double to left field after DeShields slid fielding the ball.

"It's been awhile since I've been out there on the mound, so it was good to get out there and go mix it up, and help this ballclub win a ballgame," Griffin said. "Had those like first-day-of-school jitters a little bit last night and stuff. I was excited and a little nervous."

NOTES: Minnesota LHP Glen Perkins pitched an inning for Class A Fort Myers as he recovers from shoulder surgery performed last season. Manager Paul Molitor said Perkins likely would move his rehab to Double-A Chattanooga if all went well on Thursday. ... To make room for RHP A.J. Griffin's return to the roster, Texas optioned RHP Clayton Blackburn to Triple-A Round Rock. Griffin takes the open spot in the rotation after RHP Yu Darvish was traded to the Los Angeles Dodgers. ... Twins RHP Trevor May (Tommy John surgery) played catch for the first time since undergoing surgery. ... Molitor announced that RHP Kyle Gibson would be recalled to fill in the open rotation spot after LHP Jaime Garcia was traded this week. Gibson will start Saturday.