Chris Davis hits a grand slam in 10th as Orioles beat Oakland

With one big swing, Chris Davis turned a tense extra-inning game into an Orioles victory.

Tied 3-3 in the 10th, Davis hit a grand slam on a 3-2 pitch from Oakland right-hander Arnold Leon to provide the Orioles a 7-3 lead. They won by that margin to take two of three in the series at Oakland.

In winning for the ninth time in the last 12 games, the Orioles improved to 55-52 for the season. They are 27-18 on the West Coast since 2012.

The 10th began with a Caleb Joseph single off Leon. He went to third on Manny Machado's single, and the A's then intentionally walked Gerardo Parra to load the bases. After Adam Jones popped out, Davis hammered his slam to left center. With 79 RBIs, he now has the American League lead by one over Toronto's Josh Donaldson.

It was Davis' 28th homer of the year. It was his sixth career grand slam and the Orioles' fourth on the season. Davis has two. He also hit a slam on July 25 at Tampa Bay. Over his last 15 games, Davis has nine homers and 26 RBIs. Over his last nine games, he has six homers and 19 RBIs.

Earlier, each team scored a run in the third inning. Jonathan Schoop led off the inning with a double for his ninth hit in his last 15 at-bats. He scored on Nolan Reimold's single. Oakland matched that during a messy last of the third for Wei-Yin Chen when he issued three walks and a double and threw 36 pitches. Still, he gave up just the one run.

Oakland scored twice in the fourth for a 3-1 lead. Marcus Semien doubled in both runs, giving him five RBIs the past two days. The Orioles tied it 3-3 in the sixth with four singles that knocked out A's starter Kendall Graveman. Jimmy Paredes and J.J. Hardy had two-out RBI singles. Paredes is now batting .520 (13-for-25) when batting with runners in scoring position and two outs.

Chen had a second straight shaky outing and did not get a decision this afternoon. He gave up four hits and three runs over five innings. Over his past two starts, Chen has allowed nine runs in 8 1/3 after going 11 consecutive starts giving up three or fewer runs.

The Orioles bullpen today combined to pitch five scoreless innings as Brad Brach, Darren O'Day and Zach Britton held the A's at bay. Britton got the win to improve to 2-0 with 2 1/3 scoreless innings, throwing 21 pitches.

Oakland falls to 48-61 and missed out on a lot of scoring chances today. The A's went 1-for-13 with runners in scoring position and left eight runners on base.

After taking Thursday off, the Orioles' road trip continues at Anaheim with three against the Los Angeles Angels. On Friday night, Kevin Gausman (2-2, 3.97 ERA) faces left-hander Andrew Heaney (5-1, 1.97 ERA).