OAKLAND, Calif. (AP) -- Chad Qualls stared into his locker, going over how things got away from him.
It was a sinking feeling for the Houston Astros and the sinkerballing reliever.
Houston lost its sixth in a row Saturday when Josh Reddick hit an RBI single that capped a three-run rally in the ninth inning that lifted the Oakland Athletics to a 4-3 victory.
"It's frustrating, especially for me," Qualls said. "It was a chance to win the game. (Brett) Oberholtzer pitched his heart out, he did a heck of a job. To come away with nothing is disappointing."
Oberholtzer, who spent Friday night in bed feeling ill, gave the Astros a good outing. Good enough to win most days.
"He did a tremendous job to go out and give us the start he gave us," Astros manager Bo Porter said. "It's a tough loss, especially as well as we played."
Oberholtzer allowed one run on eight hits in 5 2-3 innings. He walked two and struck out three.
Anthony Bass inherited a tight situation in the sixth, walking Coco Crisp to load the bases with two outs before inducing Jed Lowrie to pop up to shortstop.
Bass and Matt Albers got the Astros to the ninth still holding onto a 3-1 lead.
"All week long I have been under the weather," Oberholtzer said. "The last two days were the roughest. I had to get out of bed, get into the hot tub and get ready to pitch. Sure it's tough, but that's baseball."
Qualls (0-1) gave up a home run to Lowrie leading off the ninth. He walked Josh Donaldson and Yoenis Cespedes singled before Qualls struck out John Jaso.
"My sinker was flat and looking back on it, I didn't get any ground balls, which is surprising for me," Qualls said. "I was just feeling like I was getting into a groove when I got sick, but that's no excuse. You have to go out and get outs. I'll get it back."
Alberto Callaspo singled in the tying run and Reddick singled home the game-winner.
"Our bullpen has been taxed and he was the most rested," Porter said. "We had the right guys out there. We just didn't get it done."
Jonathan Villar homered and scored twice for the Astros.
Dan Otero (3-0) pitched the ninth for the win after starter Scott Kazmir had gone eight strong innings.
A day after scoring seven runs in the first inning and hitting four home runs overall, the A's were kept mostly quiet until their outburst in the ninth.
The Athletics' rally in the ninth spoiled a solid effort from Oberholtzer, who remains winless in four starts. He pitched with runners on in each of the first five innings but limited the damage each time.
The Astros got to Kazmir early when Villar homered on an 0-2 pitch in the third. Villar also doubled off the wall in left-center in the fifth and scored on a throwing error by catcher Derek Norris.
Chris Carter doubled and scored on Matt Dominguez's RBI single in the fourth to put the Astros back in front.
The game was halted briefly with two outs in the top of the eighth when umpires lost track of the pitch count. A meeting was held near the mound before crew chief Mike Winters went to replay for clarification.
NOTES: Cespedes reached on an infield single in the fifth to extend his hitting streak against Houston to 14 games. ... Astros rookie outfielder George Springer doubled in the ninth and has a hit in all four games since being called up from the minors on Wednesday. ... RHP Jesse Chavez, winless in three starts despite a 1.35 ERA, pitches the series finale for Oakland. RHP Brad Peacock (0-1) makes his first start for Houston after opening the season in the bullpen.