Brett Tomko earned his 100th major league victory in style.
"If you're going to do it, do it the right way," said Tomko, who threw 114 pitches in his second career shutout. "That makes it more memorable."
Released by the New York Yankees on July 29, Tomko (5-3) struck out three and didn't walk a batter in his 13th career complete game. He outpitched Scott Feldman, snapping the right-hander's seven-game winning streak.
Tomko retired the first two batters in the ninth inning before Julio Borbon singled to left. The 36-year-old journeyman finished things off by retiring Elvis Andrus on a grounder to shortstop.
"We were going to let him go," Oakland manager Bob Geren said. "Obviously, his pitch count wasn't high. We were going to give him every opportunity to finish as long as the game wasn't in jeopardy."
The Rangers have lost three of their first four on a nine-game homestand, falling 4½ games behind Boston for the AL wild card. It's the farthest Texas has been out of a playoff spot all season.
Texas was shut out for the second consecutive game and has not scored in 19 innings.
"It's frustrating," Ian Kinsler said. "We didn't have a good night. We've had a rough couple games."
Feldman (16-5) came into the game on the best run of his career.
Over his previous four starts, the right-hander allowed only earned run in 26 1-3 innings for a 0.34 ERA. He added five more scoreless innings before the A's finally touched him up.
Feldman, tied for second in the AL in wins, gave up six runs and six hits in 6 1-3 innings. The right-hander lost for the first time since July 29.
"We want to put ourselves in as good a position as possible and we haven't done that the last two days," Feldman said. "Regardless, we're still in this thing. We just need to show the character we've shown all year and move on."
Ryan Sweeney had four RBIs and Adam Kennedy added three more as last-place Oakland won for the sixth time in eight games.
Feldman allowed a second-inning double to Scott Hairston, then retired his next 10 batters. The A's finally broke through with three runs in the sixth and four in the seventh.
Daric Barton doubled leading off the sixth and advanced to third on a fielder's choice.
Kennedy hit a roller between the mound and first that Chris Davis fielded, but the first baseman's throw home was late and Barton scored on the infield single to break the scoreless tie.
Sweeney and Kurt Suzuki each had two-out RBI doubles to extend Oakland's lead to 3-0.
"I didn't execute my pitches or throw the ball where I wanted to," Feldman said.
Tomko, who has a 100-102 career record, allowed one hit through four innings. He gave up leadoff singles in the fifth, sixth and seventh, but all three runners were erased by double plays to end the scoring threats.
His only other shutout was Aug. 26, 2004, with San Francisco against Florida. His previous complete game came in 2005 for the Giants.
"It was easy to fall into a good pace," Tomko said. "Once we got some runs and built a lead, I could smell it a little bit."
Feldman was removed in favor of Jason Grilli after loading the bases in the seventh. Grilli gave up an RBI single to Rajai Davis and a three-run double to Sweeney.
Kennedy added a two-run single in the eighth.
NOTES: Texas 3B Michael Young is still rehabbing a strained hamstring. Young said he'll know on Thursday, an off day, when he'll be able to return to the lineup. ... Oakland RHP Vin Mazzaro, who has missed his last two starts due to right shoulder tendinitis, had another bullpen session. The team is trying to decide whether to shut down Mazzaro for the rest of the season. ... Andrus singled in the seventh to extend his hitting streak to 16 games, a Rangers rookie record.