HOUSTON -- Danny Valencia homered twice, including a go-ahead two-run shot in the eighth inning, to help the Oakland Athletics to a 4-3 victory Friday night that sent the scuffling Houston Astros to their fifth straight loss.
The recent skid has allowed the first-place Texas Rangers to move 2 1/2 games ahead of the Astros in the AL West.
Oakland trailed by a run with one out and one on in the eighth when Valencia launched a pitch from Pat Neshek (3-6) into the seats in left field to make it 4-3. Valencia had a solo shot in the fourth inning, his second career multihomer game and the first since 2010.
The Astros had a 3-0 lead after three innings thanks to two RBI from Jed Lowrie and a home run by Chris Carter.
Josh Reddick and Valencia hit back-to-back homers to start the fourth and cut the lead to 3-2.
Drew Pomeranz (5-5) struck out two in a perfect seventh for the win and Ryan Dull pitched a scoreless ninth for his first career save.
Houston starter Mike Fiers allowed two runs and five hits in six innings in his first appearance at Minute Maid Park since his no-hitter on Aug. 21, against the Los Angeles Dodgers. Reddick's homer was the first earned run Fiers allowed in 17 1/3 innings at home since being traded to Houston.
Felix Doubront went six innings for Oakland, yielding five hits and three runs with four strikeouts.
The Astros couldn't do anything after building the early lead. Jake Marisnick singled with two outs in the fourth before Oakland retired the next 15 batters. Colby Rasmus walked with two outs in the ninth, but pinch-hitter Preston Tucker struck out to end the game.
An RBI single by Lowrie gave Houston a 1-0 lead in the first. Carter's 19th homer -- and Houston's 200th this season -- came in the second inning to make it 2-0.
Jose Altuve singled to start the third and scored on a sacrifice fly by Lowrie to push the lead to 3-0. Altuve got a mouth full of dirt and almost knocked down home plate umpire Toby Basner when his momentum from the slide pushed him through the umpire's legs.
Sam Fuld robbed rookie Carlos Correa of a hit in the third when he made a diving catch in midair for the first out of the inning. Fuld smiled and shook his head after getting up and an incredulous Correa shouted "No way" before heading to the dugout.
Fiers was shaken up in the second when he was struck in the side by a liner hit by Brett Lawrie. Trainers spoke to him for a minute before he took a few warmup pitches and remained in the game.
Athletics: OF Billy Burns was out of the lineup for the eighth straight game on Friday because of tightness in his right hamstring, but he entered the game as a pinch-hitter in the seventh inning. ... C Stephen Vogt, who hasn't played since Sept. 6 because of a groin injury, is improving and worked out before Friday's game.
Astros: OF Carlos Gomez missed his sixth straight game with intercostal discomfort. Manager A.J. Hinch said he's getting better, but is probably still a few days from returning because he isn't yet able to swing a bat.
Oakland's Sonny Gray (13-7, 2.56) opposes former Athletic Scott Kazmir (7-10, 2.63) when the series continues Saturday. Gray is 4-2 with a 1.88 ERA in six career starts against the Astros. Kazmir, who was traded to Houston in July, allowed seven hits and four runs in a loss to Oakland on Sept. 8.