Athletics 20, Red Sox 2: Brandon Moss went 4-for-5 with a homer and four RBIs and Josh Reddick hit a grand slam as host Oakland pounded Boston en route to its seventh straight win and a season-high offensive output.

Brandon McCarthy pitched 6 1/3 solid innings and George Kottaras homered and drove in five for the wild-card leading Athletics, who are a game up on the second-place Baltimore Orioles and three games clear of the Tampa Bay Rays in the American League race.

Oakland, which reached 20 runs for the fourth time in club history, made quick work of rapidly fading Boston on Friday, pushing across four runs in the second inning and knocking starter Aaron Cook out with two more in the third. Moss doubled in a run in both rallies and scored in each inning on singles by Jonny Gomes.

Cook (3-8), a sinkerball specialist, failed to get the ball down and managed to record only two of his eight outs on the ground. Josh Donaldson capped the uprising in the second by drilling his fifth home run off the railing above the scoreboard in left-center.

The Boston bullpen was not much better. Moss got to Alfredo Aceves for his 15th home run - a two-run shot - in the fifth and former Red Sox catcher Kottaras reached Daniel Bard for a solo blast in the sixth.

McCarthy (8-5) was the recipient of all that support and ended up with the easy win after surrendering two runs on eight hits.

Moss, who also came up through the Boston system, and Kottaras struck again during a nine-run rally in the seventh that turned the game into a laugher. Kottaras drove in Moss with a two-run single early in the spurt and Reddick, who was traded from the Red Sox to Oakland last winter in the Andrew Bailey deal, emphatically capped the rally with his second career grand slam.

Kottaras belted a two-run homer in the eighth, combining with former Boston players Moss and Reddick for three homers and 13 RBIs in the contest.

Jarrod Saltalamacchia hit a solo home run for the Red Sox, who have lost four straight.

GAME NOTEBOOK: Moss is batting .769 (10-for-13) with three home runs and nine RBIs in four career games against Boston. … The A’s will bring RHP A.J. Griffin (shoulder) back for his first start in nearly a month on Saturday. … Oakland recalled LHP Pedro Figueroa from Triple-A Sacramento and optioned RHP Jim Miller to Class A Stockton. … Bard was making his first appearance for the Red Sox since June 3, when a failed experiment as a starter resulted in the right-hander being sent down to Triple-A Pawtucket.