ANAHEIM, Calif. (AP) -- No matter how badly Garret Anderson may be slumping, he's always a dangerous hitter.
The win increased their lead in the AL West over Oakland to 4 1/2 games.
"I'm still confident and I don't lose confidence in my ability to hit," said Anderson, who turned 36 on Monday. "You just keep plugging away because you know things are going to turn. The most important thing is not to panic. I mean, I'm not going to hit five home runs in one game to add to my stats. You have to chip away at it one day at a time."
Anderson, the Angels' career leader in games played, hits, RBIs, runs scored, doubles and total bases, is one of two players in franchise history with four seasons of 100 or more RBIs. The other is Guerrero. But this season, Anderson is hitting only .259 with 37 RBIs in 76 games.
"I have expectations of myself, and yeah, it's frustrating," he said. "But we're a first-place team and we're winning games, so it's really kind of hard to hang your head when you're playing well as a team."
Casey Kotchman greeted Alan Embree (1-3) with a ground-rule double leading off the eighth. After a sacrifice bunt by Maicer Izturis, pinch-runner Reggie Willits scored on Guerrero's ground single through the left side. Anderson then drove a 3-1 pitch to right for his seventh homer and second in 43 games.
"I was just looking for the fastball, trying to react on it and not do too much," Anderson said. "He's a fastball pitcher. That's what he's made his living doing. I got a pitch out over the plate and did something with it. A couple of weeks ago in Oakland, he got me out with the same pitch."
Anderson is hitting .321 lifetime against Oakland with 25 homers and 115 RBIs.
"He's a very good clutch hitter and he has been for a very long time," said Oakland second baseman Mark Ellis, who gave the A's a 3-2 lead in the eighth with a solo homer. "Anderson always seems to get big hits against us, and tonight was no different."
Embree has allowed 12 earned runs in 16 innings over his last 19 appearances since May 13, after posting a 2.60 ERA in his first 20 appearances. The 15-year veteran, who won a World Series ring with Boston in 2004, had a career-high 17 saves last season while Huston Street was on the disabled list.
"Alan's been great the last couple of years for us, so we definitely were confident going into the eighth inning," Ellis said. "But you've got to give them credit, though. They put together some good at-bats against a tough pitcher."
Francisco Rodriguez pitched a perfect ninth for his major league-leading 33rd save in 35 chances. The two-time All-Star is one away from John Smoltz's 2003 record for most saves at the All-Star break.
Angels right-hander Ervin Santana allowed two runs and eight hits in seven innings and struck out seven.
"He's been good every time he's pitched against us," Ellis said. "He's got a good fastball, good stuff, he mixes it up real well and he throws that breaking ball for a strike. Even when you get into a hitter's count, you're not guaranteed to get a good pitch to hit."
Scot Shields (4-2) relieved him and Ellis hit his ninth homer. Ellis has the highest road batting average in the AL (.339) and the lowest at home (.193).
Rookie Brad Ziegler relieved A's starter Rich Harden, pitching two perfect innings and striking out three. The side-arming right-hander has not allowed a run in 15 innings spanning his first 14 big league appearances. The longest scoreless stretch by an Oakland pitcher to start a career is 15 1/3 innings, by Steve Chitren in September 1990.
Harden, trying to become the first Oakland starter to begin a season 6-0 since Dave Stewart in 1990, allowed two runs and five hits over five innings and struck out five. The no-decision was the seventh for the right-hander, who has allowed two runs or less 10 of his 12 starts.
After watching his team score just two runs over its last 37 innings, Angels manager Mike Scioscia shuffled his lineup dramatically. Kotchman batted second for the first time in his big league career. Izturis started in the third spot for the first time this season, as did Howie Kendrick in the eighth hole.
Kendrick doubled his first time up after Gary Matthews Jr. was hit by a pitch to open the third inning. Jeff Mathis followed with a sacrifice fly and Kendrick scored on a groundout by Kotchman, tying the game 2-all.
The Angels had failed to score more than one run in each of their previous four games. It was the franchise's longest such streak since May 13-18, 1969, when they played six straight without scoring two or more and were shut out three times. ... The Angels' 3.31 team ERA in June was the second-best in the majors behind Oakland's 3.24.