BALTIMORE -- The Oakland Athletics knew they had the potential to be one of the best teams in the majors.

They're now putting that talent on full display, and the results have thrust the surging A's to the brink of the best July in franchise history.

Yoenis Cespedes and Chris Carter hit two-run homers to back an effective pitching performance by Bartolo Colon, and Oakland beat the Baltimore Orioles 6-1 Saturday night for its ninth win in 10 games.

Jemile Weeks had three hits and scored twice for the A's, who are 18-3 (.857) in July. With one victory in the next three games, they'll finish the month with a better winning percentage than the 1931 club (26-7, .788).

"It's been impressive -- I think for a lot of people, surprising," Weeks said. "For me, I always knew that this team was going to be somebody that could make some noise, and we're just starting to show that now. It's pleasing to see at this point."

Oakland has scored 40 runs in its last four games, including 16 in Toronto on Wednesday and 14 against the Orioles in the series opener. Saturday night, the A's combined offensive firepower and strong pitching to move in position for a sweep of fading Baltimore.

"Pitching's been our strength all year," manager Bob Melvin said. "We've come around offensively here recently. Certainly, the last month's indicative because of our record, but the pitching's been there all year."

Colon (7-8) scattered seven hits over 5 2/3 shutout innings, striking out five and walking one, to earn his first win in six starts since June 12. The 39-year-old is 12-8 with a 3.10 ERA lifetime against Baltimore, dating to 1998 when he pitched for Cleveland.

Nick Markakis' ninth-inning homer off Evan Scribner enabled the Orioles to avoid being blanked for the eighth time. Baltimore went down in order only once but stranded 11, went 0 for 6 with men in scoring position and lost for the fifth time in six games.

"They're trying. It's just not happening," manager Buck Showalter said. "I see them trying firsthand. It's not for lack of effort or lack of attention to what's causing it. When they do hit the ball on the button and it's right at somebody, it's frustrating. But if they keep going it will happen. It's not like it hasn't happened all year."

Tommy Hunter (4-6) gave up five runs and seven hits in 5 1/3 innings. The right-hander has yielded 24 home runs this season, at least one in all but two of his 16 starts.

"They hit two pretty darn good pitches," he said. "Outside of that, it is what it is."

Oakland broke on top in the fourth when Weeks led off with a single and Cespedes hit his 14th home run. The Orioles got a hit in each of the first four innings but failed four times to produce with runners in scoring position.

The Athletics made it 3-0 in the fifth. Kurt Suzuki hit an opposite-field double to right and scored on a single by Eric Sogard.

Carter chased Hunter in the sixth with a drive to left after Seth Smith hit a leadoff single. It was Carter's eighth homer since rejoining the A's on June 29.

"We're seeing Chris Carter [be] the guy we all hoped and anticipated him being," Melvin said. "Right now, he's quite a force and one of the reasons that, offensively, we've been so good this month."

In the bottom half, the Orioles got singles from Wilson Betemit and Mark Reynolds before Jordan Norberto struck out Omar Quintanilla to end the inning.

Adam Jones grounded out in the Baltimore seventh with two outs and runners on second and third.

Weeks singled and scored on a triple by Cespedes in the eighth.

Notes

• After the game, the Orioles optioned RHP Miguel Socolovich to Triple-A Norfolk.
• A's leadoff hitter Coco Crisp left in the eighth with tightness in his left hamstring.
• Baltimore DH Jim Thome did not play because of back spasms.
• Orioles 2B Brian Roberts (groin strain) began a minor league injury rehabilitation assignment with Class A Aberdeen on Saturday. Showalter said Roberts would be reevaluated after two games there.
• Baltimore C Matt Wieters reported that his tight right biceps felt much better and said he expected to play Sunday. He has missed two games with the injury.
• Oakland OF Josh Reddick was absent from the starting lineup a day after he crashed into the right-field scoreboard to make a game-ending catch.
• Travis Blackley (3-2) makes his first career start against Baltimore in the series finale. Wei-Yin Chen will pitch for the Orioles.
• Oakland LHP Dallas Braden's recovery from shoulder surgery was stalled in Arizona when he suffered a strained left groin while throwing. He has been shut down.