OAKLAND, Calif. -- Rookie right-hander Daniel Gossett threw six strong innings, and the Oakland Athletics defeated the Houston Astros 11-1 in the first game of a doubleheader on Saturday afternoon at the Oakland Coliseum.

Gossett (4-8) allowed one run on five hits with a career-high seven strikeouts and three walks.

The A's (61-80) won their third straight game and defeated the American League West-leading Astros (86-55) for the second straight time after dropping 10 straight to them at the Coliseum.

Houston right-hander Charlie Morton (11-7) gave up three runs (two earned) on six hits over five innings. He struck out eight and walked three.

A's rookie center fielder Boog Powell, who had a game-tying solo home run in the ninth inning of Oakland's 9-8 walk-off win Friday night, went 2-for-4 with a double, two RBIs, a walk and three runs. Khris Davis had two hits and drove in two, giving him 101 RBIs for the season.

The A's grabbed a 3-0 lead in the second inning. Matt Olson hit a leadoff double to right-center, moved to third on a ground out and scored on Matt Chapman's opposite-field triple down the right-field line. Powell brought Chapman home with a single to left and raced to third when first baseman Tyler White couldn't catch Morton's pickoff attempt.

Powell scored on an error by Morton, who booted Marcus Semien's ground ball.

The Astros cut Oakland's lead to 3-1 in the fifth when Max Stassi lined a leadoff single to center, went to second on a wild pitch and scored on Alex Bregman's two-out double.

Oakland extended its lead to 6-1 in the sixth. Powell greeted reliever Tyler Clippard with a leadoff double to right-center field. Clippard walked Semien and Matt Joyce to load the bases with one out before walking Jed Lowrie, forcing in a run. Davis grounded a two-run single to center off reliever James Hoyt.

The A's added five runs in the eighth when Reymin Guduan gave up a double to Lowrie and walked five batters, forcing in three runs, before infielder J.D. Davis, who doubled as a reliever in college, took over. Davis walked in a run and gave up a RBI single to Joey Wendle in his second career relief appearance.

NOTES: Astros C Max Centeno left the game during the bottom of the second inning after being hit in the facemask with the bat on A's 2B Jed Lowrie's follow through on a swing. He was evaluated for a concussion. Astros C Max Stassi, a former A's minor-leaguer, replaced Centeno. ... Astros C/DH Evan Gattis (right wrist soreness) was activated from the 10-day disabled list after a rehab stint with Class A Quad Cities. He will start at designated hitter on Sunday against Oakland. ... Astros RHP Collin McHugh's situation remained "up in the air," one day after he left his start against Oakland because of damage to the nail on his right middle finger. "I think we're going to know more in a couple days, when he throws," Astros manager A.J. Hinch said. "He'll take a couple days off and eventually test it." ... A's C Josh Phegley made his second start since being reinstated from the disabled list on Sept. 1. Phegley went 1-for-3 with a double, an RBI and two walks. C Bruce Maxwell is expected to start the second game of the doubleheader.