George Kottaras of Scarborough, Ont., had his first career two-homer game with a two-run drive and a solo shot for Oakland, which routed the Boston Red Sox 20-2 on Friday night to match its best winning streak of the season at seven.
Brandon Moss had career highs of four hits, four RBIs and four runs, Josh Reddick hit his first career grand slam. Josh Donaldson homered for the third straight game with a two-run shot and Moss also had a two-run drive to go with a pair of RBI doubles to help back Brandon McCarthy (8-5) with a season high in runs.
"I don't know that I can ask for much more than 20 runs," A's manager Bob Melvin said.
Reddick connected for his 28th homer in the seventh off Mark Melancon as the A's scored their most runs since a 23-2 win against Texas on Sept. 30, 2000. They handed the Red Sox their most lopsided loss since a 22-1 defeat to the Yankees on Jun 19, 2000.
The A's had a season-best 19 hits and scored 20 runs for the fourth time in Oakland history, while Boston allowed 20 for the first time since Aug. 21, 2009, against the Yankees.
Oakland (74-57) matched its win total from 2011 and wrapped up an 18-10 August. The A's hit a season-high five home runs a day after getting four at Cleveland.
Oakland's nine-run seventh inning was the club's biggest since a nine-run frame last July 27 against Tampa Bay.
Jonny Gomes drove in two runs on a night he helped honour the Little League World Series players from his hometown of Petaluma in Northern California's wine country.
McCarthy won back-to-back starts for the first time since June, and it's good timing with the A's leading Baltimore by a game in the AL wild-card race heading into the final month. The right-hander missed all of July while on the disabled list for a second time this year nursing a strained throwing shoulder.
Jarrod Saltalamacchia hit a two-out solo homer in the fourth for Boston, which lost its fourth straight game after being swept by the Angels in Los Angeles.
"Nothing to talk about. The score was 20-2!" second baseman Dustin Pedroia said.
Added Red Sox manager Bobby Valentine: "It wasn't any fun for anyone, that's for sure, except for the guys on the other side."
Oakland returned from a 6-1 road trip to notch another impressive win on a night when the Petaluma Little Leaguers, third in the Little League World Series, played catch with the A's on the field before the game and were honoured in a pre-game ceremony.