OAKLAND, Calif. -- The Houston Astros' game plan, according to George Springer, was to attack Oakland Athletics right-hander Sonny Gray early before he could get in a groove.

Springer led the way, launching a leadoff home run in the first inning off Gray into the left-center field seats at the Oakland Coliseum. The Astros scored five runs in the first inning and went on to an 8-4 victory Tuesday night.

"He's tough," Springer said of Gray. "You got to hit him early. You can't let him settle in. We were able to scratch across some hits in the first inning, which was big."

Springer hit Gray's 3-1 pitch for his 21st homer of the season. He hit his eighth career leadoff home run, tying the franchise record he already shared with Craig Biggio. He also homered for his third consecutive game.

"We're wowed by him, because he's setting such a great tone at the top of the order, and doing it with great power now, obviously," Astros manager A.J. Hinch said. "The first at-bat of the game, you've got to be ready. He's kind of must-see TV at the top of the order."

The Astros won for the eighth straight time at the Coliseum and beat Oakland for the 13th time in the past 14 games. They've won the first two contests of the four-game series and own the best record in the major leagues at 48-24.

Astros rookie right-hander Francis Martes (2-0) allowed three runs over 5 2/3 innings. He gave up six hits, struck out four and walked three in his second career major league start and third appearance. When he took the mound, Martes had a five-run lead.

"It's the most confident situation for any pitcher if you're pitching ahead with the lead," Martes said. "You're not going to throw strikes right down the middle, but you can challenge hitters."

Carlos Beltran went 2-for-4 with a solo home run, his 10th blast of the season, for the Astros. Josh Reddick came off the seven-day concussion disabled list and went 2-for-4 with a double, a run and a walk. Alex Bregman went 2-for-3 with two RBIs and a walk.

Gray (2-3) gave up five runs on seven hits over five innings. He struck out five, walked four and threw 108 pitches, 60 for strikes. Gray is 0-2 over his past five starts and hasn't won a game since May 24 against Miami.

"In the first, I kind of got away from the game plan a little bit and started to leave some balls kind of over the middle more," Gray said. "After that, I was able to battle through a couple innings and get through five, but I really dug us a big hole there in the first. Against a team like that and an offense like that, giving them a five-spot in the first, it's tough on the rest of the guys."

Khris Davis went 3-for-4 with two doubles, one RBI and one run for the A's. Chad Pinder hit a solo home run in the third.

Houston sent 10 batters to the plate in the first inning and forced Gray to throw 38 pitches. Springer led off the game with a no-doubt home run. Then Reddick walked and went to second on Jose Altuve's bunt single.

Gray got Carlos Correa to ground into a double play. But Brian McCann doubled Reddick home, Beltran walked, and Yuli Gurriel sent an RBI double to left-center, making it 3-0.

Bregman singled sharply to center, driving in Beltran and Gurriel, increasing Houston's lead to 5-0.

"We've talked about how starters are a little more vulnerable in the first inning than other innings," A's manager Bob Melvin said. "Just couldn't stop the bleeding there."

Oakland cut Houston's lead to 5-1 in the bottom of the first when Jed Lowrie lined a two-out single and scored on Khris Davis' double off the right-center wall.

The A's made it 5-2 in the third on Pinder's 448-foot blast into the left-center field seats, his ninth homer of the season.

Oakland scored another run in the fourth inning as Khris Davis lined a leadoff single, went to third on Yonder Alonso's double and scored on Ryon Healy's sacrifice fly.

The A's cut Houston's lead to 5-4 in the seventh. Rajai Davis lined a double to right off reliever Michael Feliz and scored on Jaycob Brugman's one-out single.

The Astros answered with two runs in the eighth to make it 7-4. After Bregman hit a leadoff double, Liam Hendriks walked Jake Marisnick and then walked Altuve with two outs, loading the bases. Correa lined his next pitch to center for a two-run single.

In the ninth, Beltran homered to right against A's rookie Michael Brady, who made his major league debut.

NOTES: Astros RHP Lance McCullers Jr. (lower back discomfort) will come off the disabled list Saturday and start against the Seattle Mariners, manager A.J. Hinch said Tuesday. McCullers, who has been on the disabled list since June 12, is 6-1 with a 2.58 ERA in 13 starts this season. ... Astros RHP Charlie Morton (right lat strain) will begin a rehab assignment Thursday with Triple-A Fresno. Morton, who threw a 50-pitch bullpen session Monday, has been on the disabled list since May 28. He is 5-3 with 4.06 ERA in 10 starts for the Astros this season. ... Oakland 3B Matt Chapman (left knee infection) missed his second straight game and continued being treated with antibiotics. "It's getting better," the rookie said. "It's better than yesterday." A's manager Bob Melvin said Chapman is still day-to-day. ... The A's signed OF Austin Beck, the No. 6 overall pick in baseball's 2017 draft. Beck took pre-game batting practice with the A's. "It's really exciting," Beck said. "it's kind of always what you dreamed of doing as a little kid. The work's just starting." Beck will report Wednesday to the A's farm team in the Arizona League.