AP Sports Writer
MINNEAPOLIS (AP) -- Scott Diamond finished last season as the only pitcher assured of a spot in Minnesota's rotation.
One year later, the left-hander isn't sure of much, starting with getting the ball to go where he wants it to.
A.J. Griffin allowed just two hits in seven innings, and the Oakland Athletics beat Diamond and the Twins 8-2 on Thursday afternoon to increase their division lead heading into a three-game series at second-place Texas this weekend.
Josh Reddick homered and had three RBIs for Oakland, which has a 3½-game edge over Texas in the American League West, the largest for the A's since Aug. 3. Diamond was in Triple-A then, sent down two days earlier after another shaky start. He went 4-0 with a 2.41 ERA in six turns for the Rochester Red Wings, bringing confidence he could carry that over to the Twins in these final weeks.
But this return was more of the same for Diamond (5-11), who finished only 4 2-3 innings while allowing six hits, five runs (four earned) and two walks. He struck out one.
"I still saw some good signs. I was getting ahead. The sinker was OK. I think the biggest flaw today was I wasn't able to locate inside at all," Diamond said. "I was able to move some feet, but I don't think it was as effective as it could have been. I think that's what I'm going to take and work on in the pen and keep my chin up, because I still feel like I'm not that far off."
One day after scoring 18 runs against the Twins, Oakland used some two-out hitting to take a 4-0 lead in the third inning.
Jed Lowrie had an RBI single leading to a mound visit by Minnesota pitching coach Rick Anderson. Yoenis Cespedes then tripled off the wall to drive in two more runs, when center fielder Alex Presley got turned around trying to chase the ball.
"Well, it was still a rocket off the wall. Let's not forget that ball was crushed," Twins manager Ron Gardenhire said, adding: "The performance is what it is. He didn't pitch very well."
Donaldson added an RBI single in the fifth. Reddick's sacrifice fly in the sixth scored Chris Young, who tripled to lead off the inning, to make it 6-0. Reddick hit a two-run shot in the eighth inning to make it 8-1, before Presley had an RBI single for the Twins.
Overall, Diamond has allowed six runs or more in four of his last major league starts. The rotation is wide open for 2014, but this wasn't a good audition.
"I can't focus on that right now. I've got to focus and look at it as still making that transition back up and doing what has made me successful here and what's made me successful in Triple-A," said Diamond, who went 12-9 with a 3.54 ERA in 2012. "Going 4? is not it."
Oswaldo Arcia homered for the Twins, who have lost six of eight. In winning his fourth straight start, Griffin (14-9) struck out eight and walked just one batter.
Arcia's solo shot, the majors-most 34th home run allowed by Griffin this season, was the lone highlight for the Twins. The rookie right fielder, who has 12 homers in 309 at-bats, raised his average to .256 by going 2 for 4.
"He went through a stretch right before the All-Star break where he was really swinging and missing a lot, and he lost his confidence, but he went back down, got himself together and has been doing pretty decent up here," Gardenhire said. "He's still got things to learn. He still gets a little nonchalant. We saw him in the outfield today, a little sloppy out there, and there's things to learn, but hopefully he'll get there. He's a strong young man, and he can hit the baseball."
NOTES: Twins C Joe Mauer, sent home the day before because his concussion symptoms reappeared, returned to Target Field for a workout that went well. "He left feeling good," Gardenhire said. ... The A's and Twins are scheduled to play a four-game series in Oakland starting in a week. ... Twins 1B Chris Colabello was hitless in three at-bats and is in an 0-for-14 slump. ... Kevin Correia (9-11, 4.30) is scheduled to pitch for the Twins against Tampa Bay's Chris Archer (8-7, 3.19) when the Rays arrive for a three-game series starting Friday. ... Despite the loss, the Twins are still 19-10 against the AL West this season.
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