Keuchel pitched a four-hitter and Robbie Grossman homered to cap a six-run first inning that sent the Astros past the Athletics 8-1 Wednesday.
Keuchel (10-7) pitched his fourth complete game of the season, tying Dodgers ace Clayton Kershaw for the major league lead. And the Astros, 20 games under .500, won the series from the AL West-leading Athletics.
"(The A's) do a lot of things well," Keuchel said. "To get a complete game and get a win is something special in its own right."
Marc Krauss beat out Oakland's try for a double play in the first, and the Astros went on to match a season high for runs in an inning.
Keuchel struck out five and walked three.
Manager Bo Porter lauded Keuchel's "plus-command" and willingness to use his secondary pitches. As he mixed his pitches up, Kuechel kept he A's guessing and forcing the type of contact that can make for a good day.
Josh Donaldson hit his 23rd homer for Oakland's only run.
Krauss hustled for an RBI grounder that kept the first inning going. After Jonathan Singleton walked, Matt Dominguez singled home a run, and another scored when center fielder Billy Burns bobbled the ball.
"I'll tell you, I think the biggest play of the game was Jason Castro going hard into second base and Marc Krauss absolutely giving the effort in which he gave getting down the line," Porter said. "That's the way the game is supposed to be played. To both of those guys' credit, they did a tremendous job in that situation."
Hammel's day ended in the fifth when Singleton hit his eighth home run.
"He had trouble getting the ball down again and in the next couple of innings when he got the ball down he was effective," A's manager Bob Melvin said. "That's where the movement takes over, the downhill plane and everything that makes him successful. And he had a tough time finishing guys off when he was ahead."
Athletics: Outfielder Coco Crisp missed his fourth game in a row with a neck strain. Melvin said the club will know more about his condition when it returns home, but said Crisp wouldn't play Friday.
Astros: Reliever Josh Zeid is scheduled to have surgeries on both feet in the next six weeks that will end his 2014 season. Carter was out with a stomach illness.
ALTUVE EXTENDS STREAK, CESPEDES' ENDS
With his line drive single in the sixth inning Jose Altuve ran his hitting streak to 12 games tying his season high. Yoenis Cespedes was unable to continue his streak of games with an RBI, going 0 for 4 and ending his run six.
DONALDSON PUNISHES ASTROS
Donaldson's second inning home run was his fifth against the Astros this season. .
Athletics: Following an off-day Thursday, the A's will start Sonny Gray at home against Kansas City. He will go for his 13th win and build on his 2.65 ERA
Astros: Jarred Cosart (9-7, 4.41) will start Friday night at home against Toronto.