ARLINGTON, Texas (AP) -- Jeremy Giambi admitted that he was nervous in the eighth and ninth innings of Oakland's 7-6 victory over Texas on Sunday.

Each of the previous two nights, the Rangers had rallied from behind to beat Oakland.

Giambi said "it was in the back of my mind" it might happen again when Jason McDonald hit a two-run homer in the Texas seventh and Rafael Palmeiro and Ruben Mateo followed with solo homers in the eighth.

"But the Rangers had every break in the world the last two days, and this one went our way," Giambi said.

Giambi was the offensive star for the A's, getting three singles, a walk and driving in three runs as Oakland salvaged the wrapup of a wild series.

Texas won 17-16 Friday night and came back for an 11-10 victory Saturday night. The teams combined for 67 runs and 88 hits in the three-game set.

Jason Giambi, Jeremy's brother, added an RBI double in the eighth that put the Athletics ahead 7-4. He also walked twice, scoring both times, this after hitting a pair of two-run homers the previous day.

Omar Olivares (3-3) got the victory, helping himself by starting a fourth-inning double play that got him out of a bases-loaded jam. The A's also backed him with double plays in each of the next three innings.

"The double play he started was huge," Oakland manager Art Howe said. "The trouble he was in was all his own making. He walked three guys. But overall he pitched well. He made one mistake on the pitch to McDonald."

Texas, which rallied in the late innings on both Friday and Saturday, threatened to take the lead later in the eighth. Singles by Chad Curtis and Mike Lamb put with runners on first and third, but reliever Doug Jones struck out McDonald.

Jones got his first save of the season and 302nd of his career.

Oakland scored three runs in the first inning on three walks and two hits against Doug Davis (0-1).

Making his first start of the season, Davis had a 37-pitch first inning reminiscent of his major league debut last year against Toronto when the Blue Jays pounded him for 11 hits and 10 runs in 2 1/3 innings of relief.

The left-hander was in trouble again in the second after another walk and a single, then gave Rangers fans a glimpse of why he was the franchise's minor league pitcher of the year last season.

Davis retired the next 10 batters, striking out six of seven hitters from the second to fifth innings.

"I think the third and fourth innings were more indicative of the kind of pitcher he is," Texas manager Johnny Oates said. "Doug Davis has a chance to be a very good major league pitcher. Actually, he pitched the best of any of our pitchers this series. If he had pitched either of the other two nights, we'd be talking about him as the winner."

Davis lost his control again in the fifth, giving up two-out walks to Jason Giambi and Olmedo Saenz and a single to Ben Grieve that loaded the bases.

Jeremy Giambi, who singled in one of Oakland's runs in the first inning, greeted Francisco Cordero with a two-run single and Frank Menechino singled another run home.

Game notes
Mateo stretched his hitting streak to 11 games. ... With Davis striking out six, four Rangers relievers combined for 12 strikeouts, a team high for the season. ... Jason Giambi and Saenz each walked their first two times up and scored both times, accounting for four Oakland runs. ... Palmeiro's homer was his 10th of the year and 371st of his career, pushing him by Gil Hodges for No. 46 on baseball's all-time list.