OAKLAND, Calif. -- When the month of May began, Oakland A's third baseman Danny Valencia was on the disabled list due to a hamstring injury and had zero home runs.

Valencia hit his eighth home run of the month and the season Tuesday night -- all since May 6 -- and powered the A's to their fourth consecutive victory, a 7-4 win against the Minnesota Twins at the Oakland Coliseum.

Valencia also doubled, and he drove in three runs. In 21 games since coming off the DL, he is batting .359 with 19 RBIs and 18 runs.

"It's nice to be back, nice to help the team win, be relatively healthy," Valencia said. "But most importantly, winning games is the goal here, and we've been fortunate enough recently to be doing it."

The A's beat the Twins for the second consecutive game and will go for the series sweep Wednesday afternoon. Oakland has won back-to-back series heading into June.

"We feel good about ourselves," Valencia said. "We're a good baseball team. We've been a little inconsistent, but it's a long season. We're a tough group with a lot of good players in here."

A's catcher Stephen Vogt stayed hot. He went 3-for-5 with a two-run double in the eighth inning that extended Oakland's lead to 7-4. Vogt scored two runs.

Robbie Grossman went 3-for-4 with three doubles, drove in a run and scored twice for Minnesota.

Miguel Sano, who leads the Twins in home runs (11) and RBIs (27), left the game in the top of the third inning with a strained left hamstring after grounding into a fielder's choice. After the game, Twins manager Paul Molitor said Sano would go on the 15-day disabled list and outfielder Max Kepler would be called up from Triple-A Rochester.

"Hopefully he'll be here tomorrow by game time," Molitor said of Kepler. "It's certainly tough. Injuries, you got to deal with them along the way. They get bunched up once in a while, and you have to make due. You call up people, and they get an opportunity and hopefully they perform."

Valencia went 2-for-4 with a walk and scored two runs. His two-run blast in the third inning was his first career home run against Minnesota, which drafted him in the 19th round in 2006.

A's left-hander Eric Surkamp, who was recalled Tuesday from Triple-A Nashville, gave up three runs on eight hits over 4 1/3 innings and got a no-decision in his sixth major league start of the season.

"Did just enough to keep us in the game and keep us close," Melvin said.

Twins right-hander Tyler Duffey (2-4) gave up five runs on 10 hits over 4 2/3 innings. He struck out six and walked one.

"When I went out there in the first inning, I knew it was going to be a rough one just because I couldn't get locked in with that fastball and ended up not giving us a good shot," Duffey said.

A's relievers Ryan Dull (1-0) and Marc Rzepczynski combined to blank the Twins on one hit over 2 2/3 innings.

Right-hander Fernando Rodriguez gave up a run in the eighth when Grossman hit a leadoff double and Kurt Suzuki singled him home with one out, cutting Oakland's lead to 5-4.

Vogt provided the A's with an insurance run on an eight-inning RBI double.

John Axford pitched a scoreless ninth inning for his first save of the season.

The Twins took a 1-0 lead in the top of the second inning on back-to-back, two-out doubles by Grossman and Byung Ho Park.

Oakland scored a run in the bottom of the second when Marcus Semien singled and Billy Burns hit an RBI triple. Minnesota moved back ahead 2-1 with a run in the third on Sano's groundout.

In the bottom of the third, Vogt lined a leadoff single, and Valencia launched an opposite-field home run to right, giving Oakland a 3-2 lead.

"He's incredible," Vogt said of Valencia. "He's done it all year no matter where he's hitting in the order. He's so good at being aggressive on his pitch, and when he gets it, he doesn't miss it."

The Twins pulled even with a run in the fifth as Trevor Plouffe singled sharply to right with one out and scored from first on Grossman's double.

Oakland scored two runs in the bottom of the fifth. Vogt led off with a single and scored on Valencia's double to the left-center alley. Semien brought Valencia home with a two-out double to left-center.

NOTES: A's RHP Sonny Gray (strained right trapezius) threw 50 pitches, including his last handful to hitters, before Tuesday's game against Minnesota. "It feels really, really good, and it feels loose," said Gray, who has been on the 15-day disabled list since May 21. Gray said a cortisone shot and treatment helped get rid of tightness in the strained muscle. ... A's RHP R.J. Alvarez (right elbow surgery) will begin a rehab assignment Friday with Class A Stockton. He will pitch one inning. ... A's RHP Zach Neal was optioned to Triple-A Nashville, opening a spot on the 25-man roster for LHP Eric Surkamp, who was recalled from Nashville and started against Minnesota. ... Twins CF Byron Buxton, who was called up late Monday night from Triple-A Rochester, started Tuesday and went 1-for-4. ... Twins 1B Joe Mauer was named the American League Player of the Week for the third time in his career.