OAKLAND, Calif. -- The Oakland A's put eight runners on base in the first six innings Wednesday against Boston Red Sox left-hander Wade Miley.

Not one of the eight scored.

Miley got himself into and out of jams all day, pitching 6 2/3 high-stress but scoreless innings, and the Red Sox defeated the A's 2-0 at the O.co Coliseum, handing right-hander Sonny Gray his first loss of the season.

The A's went 0-for-13 with runners in scoring position against Miley and 0-for-14 for the game.

"He was outstanding, he was resilient," Red Sox manager John Farrell said of Miley. "He didn't give in. He was at his best when he needed to be, and that was when there were men in scoring position."

In other words, in Miley's first four and five of his first six innings against the A's. Miley said he felt like he started on the tightrope in the first inning when he walked the first two batters he faced before retiring the next three in order.

"From the first inning on, I just felt like I never had a super good feel for my fastball," Miley said. "So I was kind of just nibbling away with breaking balls and changeups, trying to mix speeds when I could. The defense made some outstanding plays, too, to get me out of jams."

Miley (2-4) allowed just five hits but walked four. He snapped a three-game losing streak and won for the first time since April 21 against Tampa Bay.

Gray (4-1) gave up one run and three hits in seven innings. He struck out nine and didn't walk a batter for the first time this season.

"I felt good," Gray said. "The ball was coming out really good. We were close to keeping them scoreless.

"Every loss is not much fun. It stinks because this was a game we more or less needed to win. You want to win series and we had the opportunity to do that. We had a lot of chances, and Miley made really good pitches when he needed to get out of some trouble."

The A's (13-23) fell to 1-11 in day games, the worst record in the major leagues, and 1-10 in series finales. They ended their six-game losing streak Tuesday night with a 9-2 victory over Boston, but they've won back-to-back games just once all season. They dropped to 1-6 against left-handed starters.

"It seemed like as the game went along we started pressing more," A's manager Bob Melvin said.

The Red Sox (16-18) took two of three from the A's and won a series of at least three games in Oakland for the first time since July 24-26, 2006.

Right-handed reliever Junichi Tazawa pitched 1 1/3 scoreless innings and closer Koji Uehara pitched a scoreless ninth for his seventh save.

First baseman Daniel Nava went 2-for-3 with an RBI and scored a run for the Red Sox. Left fielder Hanley Ramirez had two hits in four at-bats and scored a run.

Shortstop Marcus Semien tripled and catcher Josh Phegley doubled for the A's. Left fielder Coco Crisp snapped his career-long 0-for-39 skid with an infield single in the fifth and made two diving catches.

The Red Sox grabbed a 1-0 lead in the second inning against Gray. Ramirez grounded a leadoff single to right field and advanced to second on a wild pitch. Nava blooped an RBI single down the left-field line with two outs.

Boston added an unearned run in the eighth. Nava lined a leadoff single off right-hander Evan Scribner and moved to second with one out when Scribner hit catcher Sandy Leon with a curveball after getting ahead 1-2 in the count.

With two outs, second baseman Dustin Pedroia reached on an infield single and Nava raced home when Semien's throw to first sailed high and wide for an error.

In the third, Semien hit a leadoff triple, but Miley retired right fielder Josh Reddick on a popup, designated hitter Billy Butler on a fly ball and third baseman Brett Lawrie on a ground ball.

"It was horrible offense," Reddick said. "When we get guys in scoring position, we got to get them in. Marcus' leadoff triple, that run can't stay at third. I got the pitch I wanted, but I just got out in front of it a tad early."

The A's had runners on first and second with two outs in the sixth when center fielder Billy Burns hit a hard ground ball down the third base line, but third baseman Pablo Sandoval made a backhand play and threw to first for the out.

"It might have been the difference in the game, the one-hopper from Burns," Farrell said. "That's down in the corner for at least a double and probably a run in. (Sandoval's) defense at third base today was outstanding."

NOTES: Red Sox RHP Justin Masterson, who had his second straight rough start Tuesday night, will miss his start Sunday at Seattle and probably is headed to the disabled list, manager John Farrell said. Masterson had a "full exam and workup" with the team's medical staff. "There's not one specific area to the arm or shoulder that is a cause or reason why we're seeing reduced velocity and reduced action," Farrell said. "There's some fatigue that's involved." ... RHP Steven Wright is a "strong candidate" to start Sunday against Seattle. He pitched 5 2/3 innings of relief Tuesday. ... Oakland INF/OF Ben Zobrist, who underwent surgery April 28 to repair a torn meniscus in his left knee, could begin a rehab assignment Monday, manager Bob Melvin said. ... A's 1B Ike Davis (strained left quad) was out of the starting lineup for the second straight day but pinch hit in the ninth, flying out to center.