OAKLAND, Calif. -- The first time Oakland A's right-hander A.J. Griffin faced the Boston Red Sox this season, he had a nightmare at Fenway Park.
He allowed a career-high nine runs on eight hits and lasted just four innings in a 9-6 loss on April 22. He gave up two home runs that night, including a grand slam to Mike Napoli.
Griffin evened the score on Saturday night at the O.co Coliseum and helped the A's even their three-game series against Boston with a 3-0 victory.
Griffin threw eight shutout innings before giving way to closer Grant Balfour, who pitched a scoreless ninth for his 43rd consecutive save, an ongoing Oakland record. Griffin allowed six hits -- five singles and a Napoli double -- and won his third straight decision. He struck out three, walked one and improved his record to 8-6.
Red Sox left-hander Jon Lester took the loss despite a solid outing. He gave up three runs and six hits in 6 1/3 innings.
The A's remained a game ahead of Texas in the American League West, and Boston's lead in the AL East over Tampa Bay slipped to 3 1/2 games.
The A's snapped their two-game skid and ended Boston's four-game winning streak.
Derek Norris gave Oakland a 1-0 lead in the bottom of the fifth with a two-out home run off Lester. The A's made it 2-0 in the sixth when Jed Lowrie walked with one out, moved to second on Josh Donaldson's sharp single to center and scored on Yoenis Cespedes' single to left.
The A's increased their lead to 3-0 in the seventh. Former Red Sox outfielder Josh Reddick singled to left off Lester and moved to second when Norris walked. Reddick tagged up and advanced to third on rookie Grant Green's flyout to right fielder Shane Victorino in foul territory.
Facing Red Sox reliever Junichi Tazawa, Coco Crisp lined an RBI single to right, bringing Reddick home.
Norris broke a scoreless tie with a solo shot off Lester with two outs in the bottom of the fifth. Lester got ahead 0-2 in the count but sent a 91 mph fastball down the middle of the plate and Norris lined it to left field for his fifth home run of the season.
The Red Sox had a good chance to score in the first inning but came up empty. They had runners on first and second with two outs after singles by Victorino and David Ortiz. But Griffin struck out Napoli, ending the threat.
Boston stranded Victorino at second in the third inning and Napoli at second in the fourth, wasting his one-out double that hit high off the wall in left center.
The A's put two runners on in the second after back-to-back singles off Lester with two out. Lester retired Norris on a soft ground ball to first base to end that threat.
NOTES: Red Sox RHP Steven Wright was optioned to Triple-A Pawtucket, opening a roster for LHP Matt Thornton, who was acquired from the Chicago White Sox in a trade on Friday. Wright pitched 5 2/3 innings of relief on Thursday at Seattle, allowing three hits while striking out three and walking two. Red Sox manager John Farrell said Wright, a knuckleballer, is a candidate to join the rotation as the No. 5 starter after the All-Star break. ... SS Stephen Drew (right hamstring strain) "is not likely" to be activated Sunday when he's eligible to come off the disabled list, Farrell said. "We'd like to get him some at-bats on a very, very brief rehab, if that works in, coming out of the break. He's going to be rejoining us shortly right after the All-Star break." Farrell said he expects Drew to be activated during the Red Sox's first series after the break, July 19-21 against the New York Yankees at Fenway Park. Drew ran the bases hard during a lengthy pre-game workout on Saturday. ... Cespedes had a long and impressive batting practice session as he tuned up for Tuesday night's Home Run Derby. Third base coach Mike Gallego threw BP and will pitch to Cespedes at Citi Field. ... LHP Matt Thornton, acquired in a trade from the Chicago White Sox on Friday night, reported to the Red Sox some two hours before Saturday night's game. "I've been smiling pretty much all day, knowing that I was going to be on a first-place team and in a pennant race down the stretch," Thornton said.