OAKLAND, Calif. — A.J. Griffin and Grant Balfour combined on a seven-hitter and the Oakland Athletics beat the Boston Red Sox 3-0 Saturday night.

Derek Norris homered and Yoenis Cespedes added an RBI single to help the division-leading A’s end a two-game losing streak and maintain their one-game lead over Texas in the West. Oakland reached 55 wins before the All-Star break for the first time since 1975.

The A’s sputtering offense managed only one extra-base hit off Boston starter Jon Lester and one reliever, but made them hold up behind Griffin’s stellar outing.

Shane Victorino singled twice for Boston, which had won four straight.

Griffin (8-6) wasn’t crisp but still went eight scoreless innings to remain unbeaten in his last five starts.

The Oakland right-hander, who walked one and struck out three, pitched with runners on base in each of the first six innings and twice had to work out of two-on, two-out jams but escaped damage each time.

That was in stark contrast to his previous start against the Red Sox, when he was shelled for nine runs (seven earned) over four innings on April 22.

He also got help from the A’s defense. Rookie second baseman Grant Green turned an unassisted double play in the second inning after Jarrod Saltalamacchia walked, then shortstop Jed Lowrie made an impressive recovery and throw to get Dustin Pedroia in the eighth after initially bobbling the ball.

Balfour pitched the ninth for his 25th save this season and 43rd consecutive save dating to 2012.

Norris homered off Lester (8-6) with two outs in the fifth.

Cespedes, mired in a 6-for-37 slump, singled home Jed Lowrie in the sixth to make it 2-0. It was Cespedes’ first RBI this month.

Lester beat the A’s on April 24 when he allowed three runs over 5 2/3 innings, and he looked sharp early. Boston’s left-hander allowed only one runner to reach second until Norris homered, and he faced just three over the minimum through five innings.

Since opening the season 6-0, Lester has gone 2-6 with a 6.27 ERA over his last 11 starts.

Coco Crisp’s RBI single off reliever Junichi Tazawa in the seventh drove in Josh Reddick with the A’s final run.