OAKLAND (AP) — Arnold Leon was hoping to get a ground ball when he tried to throw a fastball down and away to Baltimore slugger Chris Davis.

Like so many other things with Oakland manager Bob Melvin’s ballclub this season, the plan didn’t work out.

One of the hottest hitters in the majors over the past two weeks launched his second grand slam in 12 days with one out in the top of the 10th inning and the Orioles beat the Athletics 7-3 on Wednesday.

“I didn’t execute very good so I got a homer,” Leon said. “It stayed right in the middle when he swings. I was trying to go away to get a ground ball double play, something like that, and didn’t execute with the pitch.”

Davis hit his 28th home run and third in four games on a 3-2 pitch from Leon (0-1). It came two batters after Gerardo Parra was intentionally walked to load the bases. Caleb Joseph and Manny Machado led off the inning with back-to-back singles.

It’s the sixth grand slam of Davis’ career. He also hit one against Tampa Bay on July 25.

Over his past 15 games, the Baltimore first baseman is batting .309 (17 for 55) with nine home runs and 26 RBIs while pushing the Orioles within one game of the second wildcard spot.

“I feel like I’m seeing the ball well right now, being patient for the most part,” Davis said. “These guys made some really good pitches to me throughout the series, just hitting their spots. In that situation . you know that he’s going to be careful so you go up there and you try to be selective.”

The Orioles trailed 3-1 before scoring twice in the sixth then won it in the 10th.

Closer Zach Britton (2-0) pitched a season-high 2 1/3 scoreless innings for the win.

Marcus Semien had two hits and two RBIs for the A’s, who fell to 4-7 in extra-inning games this season.

“We had some situational at-bats where we didn’t get it done,” Melvin said. “There were three or four where we had a man on second and nobody out and we don’t get him over to third and we don’t get him in. Usually in close games those will come back and bite you.”

Nolan Reimold snapped an 0-for-9 skid with an RBI single off Oakland starter Kendall Graveman in the third.

The A’s tied it on Brett Lawrie’s sacrifice fly in the bottom of the inning.

Semien, whose three-run homer sparked a 5-0 win on Tuesday, put the A’s up 3-1 with a two-run double off Wei-Yen Chen in the fourth.

Chen allowed three runs and four hits over five innings. He walked four and struck out four.

Jimmy Paredes hit an RBI single in the sixth to pull Baltimore within 3-2, two batters after center fielder Billy Burns made a leaping catch to rob Adam Jones of a home run. J.J Hardy followed with a single to drive in Davis with the tying run and chase Graveman.

Graveman struck out three and walked one in 5 2/3 innings.

Danny Valencia, claimed off waivers from Toronto earlier this week, went 1-for-5 in his Oakland debut.

TRAINER’S ROOM

Athletics: OF Coco Crisp was scratched from the lineup with a sore neck. He grounded out as a pinch-hitter in the ninth. RF Josh Reddick also did not start after sitting out Tuesday’s game with stiffness in his lower back. Reddick drew a walk as a pinch-hitter in the seventh.

UP NEXT

Athletics: RHP Aaron Brooks (1-0) pitches in the opener of a four-game series against Houston on Friday. Brooks picked up his first career win in his previous start after being called up from the minors.

Orioles: RHP Kevin Gausman (2-2) will go for Baltimore Friday in Anaheim and is looking to win consecutive starts for the first time this season