OAKLAND -- The Texas Rangers have given Cole Hamels plenty of run support since acquiring him in a trade from Philadelphia in late July.
Not that the three-time All-Star has needed much.
Hamels pitched six innings to earn his fifth consecutive win, Prince Fielder hit his 22nd homer and the Texas Rangers beat the Oakland Athletics 8-1 on Thursday to complete a three-game sweep.
The Rangers moved a season-high 14 games over .500 and extended their lead to 3 1/2 games over the idle Astros in the AL West. Texas heads to Houston to begin a pivotal three-game series on Friday that could determine the division winner.
Texas is averaging nearly six runs per game when Hamels pitches and gave the right-hander a 2-0 lead against the A's before he stepped on the mound.
"It's a very nice feeling because you don't have to be forcing anything," Hamels said. "You can really just go out there and try to be aggressive in the zone and throw strikes. That's how you win ballgames."
Adrian Beltre drove in three runs, and Delino DeShields had three hits and two RBIs for Texas.
"They've got some great energy right now, superior focus and they're on a mission," Rangers manager Jeff Banister said. "Each one of them knows where we want to go. We're not there yet so they maintain that focus."
Hamels (11-8) gave up an unearned run in the second but was otherwise stellar while improving to 5-1 in 10 starts with the Rangers. Hamels allowed four hits, walked three and struck out two.
Josh Reddick singled and scored for Oakland.
The A's have lost five straight and dropped 25 games under .500 for the first time since 1997.
Texas turned four double plays in the first five innings and outscored Oakland 26-10 in the series.
"I'm not normally a ground-ball pitcher, but it definitely helped out today," Hamels said. "It kept them from rallying. The defense was outstanding behind me."
Beltre drove in Texas' first run with an RBI single off A's starter Chris Bassitt in the first. He had a two-run single in the sixth when the Rangers scored three times and batted around.
DeShields added an RBI single in the sixth to make up for his error in the second that led to Oakland's only run when he dropped Jake Smolinski's two-out fly ball to short center.
Reddick, who singled then stole second and third, scored on the error.
Fielder hit a two-run home run off Cody Martin in the eighth.
Bassitt (1-7) gave up three runs and six hits in three innings. He walked one and struck out three in his first start since Aug. 26.
"It was important for him psychologically and physically to be back out there and perform," A's manager Bob Melvin said. "They made him work and made him throw a lot of pitches."
Athletics: RHP Edward Mujica (right hamstring strain) threw off a mound on Wednesday, and Melvin said it's possible that the veteran reliever could pitch again this season.
Rangers: RHP Yovani Gallardo (12-11) pitches the series opener in Houston trying to avoid matching his career high for losses. Gallardo, who has dropped his previous two starts, lost 12 games in 2009.
Athletics: RHP Sonny Gray (13-7) will start against San Francisco on Friday. Gray beat the Giants in his only other career start against them on July 8, 2014.