SAN FRANCISCO -- Before the A's faced Barry Zito for the first time, on May 19, catcher Jason Kendall gave his teammates a detailed scouting report on his former batterymate that, by all accounts, helped Oakland knock the former Cy Young winner out of the game before Zito could get an out in the fifth inning on the way to a 15-3 drubbing.

Zito's reaction to hearing that Kendall, a good friend, had played such a significant role in ruining his return to Oakland?

"That's what he's supposed to do," Zito said on Friday. "That happens all over the big leagues, with players switching teams all the time. Anything that gives you an edge, you have to use it. I have no problem with that at all.

"But honestly, it shouldn't matter. If I make my pitches, whether they have an idea about what I'm trying to do or not, I should be fine. If I'm not making my pitches, even a team that just has the standard information that's out there about you is going to take advantage."

On Saturday at AT&T Park, Zito again didn't make enough pitches to make the A's pay for their patient approach, and Dan Haren, in beating his former clubhouse mentor, presented yet another compelling piece of evidence in the case suggesting he should start for the American League when the All-Star Game comes here in July.

Zito threw 52 pitches in the first two innings and couldn't get an out before being yanked in the fifth, and Haren lowered his MLB-best ERA to 1.58 with seven shutout innings of five-hit work while raising his record to 7-2 as Oakland cruised to a 6-0 victory in the second game of a three-game Interleague series that concludes on Sunday afternoon.

Haren, who struck out six without a walk and threw only three more pitches than did Zito, started the season 0-2 despite a 0.69 ERA in his first two starts and hasn't allowed more than two earned runs in a start since taking a no-decision on April 13 against the Yankees.

"I wouldn't say it's more special [to beat Zito]," Haren said. "Going into the game, I was looking forward to it, but by no means am I happy because I beat him. He's a good friend of mine and a big part of my career."

"Haren looks great," Zito said. "He's attacking the zone, using all his pitches. He's just showing the league what he's all about."

"The guy's been throwing the ball well all season," added Giants outfielder Randy Winn. "He's got to be right up there with the best that we've faced. We faced [2006 National League Cy Young winner] Brandon Webb a couple days ago, and Danny Haren threw the ball just about as well as Webb did.

"He really makes it tough on you when he's throwing well."

In winning for the seventh time in eight games to move a season-high five games over .500, the A's improved to 7-2 in June and benefited from highly productive afternoons from a handful of regulars they'll need to contribute on a routine basis if they hope to get to the playoffs for the sixth time in eight years.

Third baseman Eric Chavez, who batted .228 while dealing with chronic forearm pain over the first two months of the season, continued his resurgence since the proper treatment was determined by going 2-for-5 with a double and a triple.

Shortstop Bobby Crosby, who entered the game stuck in a 7-for-48 (.146) funk, broke out with three hits, including a line-drive homer into the left-field bleachers off Zito that gave Oakland a 2-0 lead in the third.

And center fielder Mark Kotsay, who missed the first two months of the season while recovering from back surgery, snapped an 0-for-15 slide that featured a number of squared-up outs with a single in the first, scored the first run of the game, and added two more hits and an RBI.

"At this level it's all about results, and you can easily get caught up in results," Kotsay said. "But at the same point, my Spring Training was 10 games [on a] Triple-A [rehab assignment], and this isn't the Minor Leagues. Everything's just that much more difficult."

"He looks like his timing's getting there," manager Bob Geren said of Kotsay. "It takes a while to get your timing back against Major League pitching."

Asked about the importance of the aforementioned trio's bats heating up, Crosby lit up.

"It's big," Crosby said. "We've already got guys like [Travis] Buck and [Mark Ellis] swinging the bats well, and when we get four of five guys hot, with the pitching staff we have, that's when we're a really good team."

Added Haren: "I think, for a little while there, early in the season, there was a lot of pressure on [the pitching staff]. Now if you go out there and give the team a chance to win the game, there's a good chance you will win the game."

Buck, who collected a career-high four hits on Friday, went 3-for-5 with a double and an RBI and is now batting .545 (12-for-22) with four doubles, a triple, a home run and four RBIs in five games against the Giants this season.

Of Buck's 39 hits this season, 20 have been for extra bases -- 10 doubles, four triples and six homers.

"I've said this many times," Geren said. "Travis has the makings of a very special player."

Ellis homered and singled, and he's batting .353 (12-for-34) with three doubles, a triple, two homers, five RBIs and four multi-hit games in the eight games he's played since the birth of his first child, Briggs, on June 1.

Not particularly fond of talking about himself, Ellis was at his postgame best when discussing the connection between Oakland's offense clicking and Haren being on the mound.

"We have a lot of energy when Dan's out there," Ellis said. "He's had such a phenomenal year, so we don't want to let him down. We kind of let him down early in the year, so we want to get him as many wins as possible."

Haren, insistent that his focus doesn't go beyond his next start while conceding that it's a cliché, still won't engage in much talk about his All-Star status. Geren, however, will gush about his ace for as long as you'd like.

"It's kind of far away, but if it were soon, I'd say he should start," said the skipper. "It just feels like you're going to win every single time he goes out there. The competition doesn't seem to make a difference."

"I haven't played behind anybody that good in my life," Crosby offered. "To see him paint the way he does, the way his ball moves, the way he makes good hitters look bad ... I've never seen anything like it."