CLEVELAND – The A's finished off business Thursday with a 12-7 victory that completed a four-game sweep of the Cleveland Indians, and now they return for a six-game homestand that shows just how unpredictable a major league season can be.

Oakland has defied expectations and currently leads the American League wild-card race. The A's have won six straight games, they are coming off a 6-1 trip that's their best since 2006, and they continue to be one of the majors' most surprising success stories.

Things have played out much differently for the Boston Red Sox and Los Angeles Angels, who will visit O.co Coliseum for three-game series over the next week.

Both were expected to be World Series contenders but so far have fallen woefully short of expectations. Thus, this homestand doesn't look nearly as daunting as it did in April. But that doesn't alter Oakland's view of it.

"We just need to win, it doesn't matter who we play," said right-hander Jarrod Parker, who collected Thursday's win. "Anybody can show up any day and win the ballgame. We've just got to stay focused and handle it each game at a time."

The A's (73-57) did just that against the Indians (55-76), taking four straight from an inferior team that is wobbling to the finish line. After the A's took two of three from wild-card-contending Tampa Bay, they showed no letdown in Cleveland, piling up 27 runs over the final three games of the series.

Thursday's finale was not pretty, as the teams issued a combined 13 walks in a game that lasted 3 hours, 35 minutes. The most exhilarating part of the afternoon for the 14,500 in attendance was the chance to watch fighter jets rip through the blue sky above Progressive Field as part of Navy Week, which is taking place in the city.

The A's also went airborne, hitting four home runs for the fifth time this season.

And they got an unlikely spark from the bottom two hitters in their lineup.

With the score 1-1 in the fourth, catcher George Kottaras lined a three-run double to the gap in right-center. Cliff Pennington followed with a two-run homer to right off Justin Masterson that made it 6-1 and put the A's in control.

"It's huge to come up (big) in that situation," said Kottaras, whose three-run hit equaled the number of RBIs he had since joining the A's via a trade July 29.

Josh Reddick hit a two-run homer in the fifth inning. Josh Donaldson and Coco Crisp also homered.

The A's are within four games of idle Texas, the closest they've been to the A.L. West leaders since they were 3 1/2 out July 31.

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