David Murphy and Adrian Beltre slugged first- inning homers to back a solid performance from Ross Wolf, and Texas clipped Oakland, 3-1, in the finale of a three-game set.
Murphy's blast was a two-run shot and Beltre added a solo homer for the Rangers, who avoided a sweep at the hands of their division rivals.
Recalled from Triple-A prior to the game for his first major league start, Wolf (1-0) snagged his first MLB victory by giving up a run on three hits with three strikeouts and a pair of walks over five-plus innings.
"For him to come up and pitch and get his first big league win, it's cool to say you were a part of it," Rangers catcher A.J. Pierzynski said.
Brandon Moss drove in the lone run and Derek Norris added two hits for the Athletics, whose five-game win streak came to a halt.
Jarrod Parker (2-6) was charged in defeat for six hits and three runs while fanning five in seven full frames.
Wolf worked out of a two-on, none-out jam in the fifth, stranding two in scoring position. He walked Seth Smith and allowed a double to Norris before getting Eric Sogard and Adam Rosales on pop outs and Coco Crisp on a grounder to first.
The 30-year-old right-hander departed with two on and none out in the sixth for Neal Cotts, who worked out of trouble by retiring the next three batters in succession.
"I think it meant everything to anyone that's in the game of baseball that has a dream,'' Texas manager Ron Washington said. "I think he did a great job of going through a hot team."
Oakland failed to score a runner from third in the seventh against Cotts, then went quietly in the eighth facing Robbie Ross. Joe Nathan retired the side in order in the ninth to record his 14th save.
Parker was victimized early on, as Elvis Andrus singled ahead of Murphy's home run, then after Lance Berkman flied out, Beltre launched his 10th of the year to give Wolf all the help he needed.
"He threw a couple of early-count heaters that they squared up," Oakland manager Bob Melvin said of his starter. "Early in the season, that game gets away from him. It looks like he's more comfortable now."
Oakland got one back in the fourth on a sac fly from Moss to plate Crisp, who singled to start the frame and moved to third on a Yoenis Cespedes double.
Prior to Wednesday, Wolf pitched in 25 combined games with Florida (2007) and Oakland (2010), working 25 innings over that span and finishing nine contests without having made a start ... To make room for Wolf, the Rangers sent pitcher Cory Burns to Round Rock... Both teams are back in action on Friday, as Texas begins a five-game road trip in Seattle, while Oakland heads to Houston.