OAKLAND -- The 21-year-old Trevor Cahill looks more like the kid next door than a Major League pitcher. Of course, looks often form the web of deception.

Cahill has had two rough outings this season, and each time he responded with one of his best efforts. It was no different Friday night when he gave up two runs on six hits over a season best 7 1/3 innings. He walked one and struck out a season-best five.

"On a normal night in any other Major League game, he's going to win," Athletics manager Bob Geren said. "He made them earn everything."

It still wasn't enough to give Oakland a victory as the D-backs received a similar effort from Billy Buckner, who made his Arizona starting debut a successful one in a 2-1 victory over the A's.

"None of us ever had any at-bats against him," A's outfielder Matt Holliday said. "There's always a chance it can take awhile to get used to what he's throwing or what he's doing. We hit some balls hard that didn't find holes, and that's frustrating because Trevor pitched so well."

The A's lost for the sixth time in eight games and are off to their worst start since opening the 1979 season with 13 wins in their first 39 games.

"We hit the ball hard but it was right at guys tonight," A's outfielder Ryan Sweeney said. "We didn't get the breaks of hitting the gaps or hitting when we got the leadoff guy on."

Holliday hit a home run on the first pitch of the second inning, a good indication of future production for the cleanup hitter and, possibly, the team.

"Hitters of his caliber, when they get hot, they can stay hot for a long period and cause damage," Geren said. "That's a good sign. We need all the runs we can get."

Holliday hopes he's straightening things out as well.

"I hope I just find my stroke," Holliday said. "I'm not necessarily looking to hit home runs. I'm trying to hit the ball hard. I had some good at-bats and that's all you can do."

Cahill (2-4) gave up a run-scoring single to Gerardo Parra in the third and a towering home run to Chris Young in the fifth. It was just enough to get the loss.

"It's a combination of location and stuff and making pitches," Cahill said. "I've been working on off-speed command and it felt good today."

Cahill (2-4) received run support of two runs or fewer for the fifth time in nine starts.

"You just have to stay focused all the time," Cahill said. "It's nice to get a lot of runs but if you take it easy, you end up giving up seven runs."

That was a reference to his worst start the last he took the mound in Detroit, lasting 2 1/3 innings. It didn't seem to bother him Friday night.

"I've always been pretty good at putting the past behind me and maintaining the same confidence," he said. "You kick yourself that night but when you get to the park the next day, it's brand-new."

Cahill has allowed 14 of his 25 earned runs in two games. In his other seven starts, he owns an ERA of 1.87.

"It was a good bounce-back for him," Geren said. "After a rough outing you always want to follow it with a positive performance. He went beyond that. He was outstanding."