OAKLAND -- Wade Miley isn't willing to say he is pitching as well as he can, but he was certainly good enough Thursday night.

The Orioles left-hander produced his first quality start since June 1, and twice the Orioles hit back-to-back home runs on consecutive pitches to provide plenty of support in Baltimore's 7-2 win over the Oakland Athletics on Thursday night.

Miley (6-9) allowed only one unearned run and three hits over seven innings. He struck out seven and walked three while throwing 111 pitches (66 for strikes).

"I kind of struggled a little bit that first inning trying to find my command, but we stuck with it, stuck with the game plan, and it worked out," Miley said.

Closer Zach Britton, the fourth Oriole reliever, got the final out with the bases loaded for his 10th save of the season and 58th straight successful conversation over two years.

Trey Mancini hit a pair of long balls to reach 20 home runs for the first time in his brief career. Adam Jones hit his 21st home run -- a tape-measure blast -- and Mark Trumbo awoke from a slumber to hit his 18th as the Orioles produced nine extra-base hits before earning their first single as late as the eighth inning.

"All my starts are tough, but that lineup is deadly," A's starter and loser Chris Smith said. "Man, they just kept on attacking. They made the adjustments on my mistakes, and they hit them. They hit them hard and far."

Smith (0-2) allowed five runs on seven hits, including the four homers, in six innings.

The Orioles staked Miley to an early lead by scoring a run in the first before getting two home runs in the fourth.

Red-hot Tim Beckham (2-for-5) hit a ball off the top of the center-field fence for a leadoff triple in the first, and he scored when Manny Machado followed with a slow roller to third.

Jones and Mancini belted long homers to left field in the fourth after Oakland had tied the game in the first when Lowrie's sacrifice fly to right plated Rajai Davis, who led off with a single.

Baltimore pounded two more long balls in succession with one out in the sixth as Mancini and Trumbo went deep to left off Smith for a 5-1 lead.

"It was just the homers," A's manager Bob Melvin said in defense of his starter. "We got some balls up, they squared 'em up. Other than that, he had guys off-balance. ... Every mistake he made, they made him pay for it and hit homers. That's what they do when they're swinging the bat well."

The rest was up to Miley, who retired Oakland in order in the second, third and seventh innings.

"I had a couple quick innings in the middle -- second, third and fourth -- that allowed me to go deeper in the game," Miley said. "I was able to throw strikes and get ahead. I'm not exactly where I want to be -- I still don't have the fastball command I'd like -- but I'm using the breaking ball and cutter to get ahead a little more now and it's working out."

Orioles manager Buck Showalter added, "He attacked both sides of the plate. He had more than one pitch working. Guys like playing behind him, he puts zeros up."

Miley was cruising along already even before the Orioles tacked on two unearned runs in the seventh inning to boost their lead to 7-1. Beckham doubled to right with one out before Jonathan Schoop reached on an infield error. Both scored when Jones bounced a double into the left-field corner. Jones had three RBIs.

"Adam had two big hits for us tonight," Orioles manager Buck Showalter said.

Oakland rallied for a run in the eighth off reliever Darren O'Day when Jed Lowrie's second double of the game plated Marcus Semien, who led off the frame with a single. However, O'Day got out of a two-on, no-out jam with a strikeout and a double play.

NOTES: Baltimore DH Mark Trumbo was dropped to sixth in the batting order in an effort to get out of a slump. His home run snapped an 0-for-24 drought. ... Oakland 3B Matt Chapman left the game after two innings with an illness. Ryon Healy moved from first base to third, and Matt Olson took over at first. A's manager Bob Melvin said afterward Chapman was dehydrated before the game, and he didn't want to come out. ... The Orioles have hit back-to-back home runs nine times this season.