BALTIMORE -- Tyson Ross couldn't recall a time when everything unraveled so quickly in one of his starts. Each time he left a breaking ball or fastball up in the strike zone on Saturday night, the Orioles managed to find a hole through the infield.
Ross was rattled for five runs in the second inning, and the A's never recovered in an eventual 10-1 loss, their most lopsided setback of the season and one that snapped a three-game winning streak.
Ross allowed nine runs on 11 hits with one strikeout and one walk over four innings, boosting his ERA from 2.13 to 6.48.
"It's definitely frustrating when you give up a bunch of hits and a bunch of runs," Ross said. "You've got to get past it now and look forward to the next start. I just have to look back on it and figure out what I did different from the first and second innings. It's definitely a learning experience."
The A's fell back to 11-11 on the season but can move back above .500 on Sunday, when their most experienced pitcher, Bartolo Colon, takes the mound against Orioles' righty Tommy Hunter.
Prior to Ross' outing, pitching had carried the A's, who entered the game with the lowest ERA in the American League, at 2.68. But once the Orioles continued to pile up runs, the A's bats simply could not cut into that lead -- a problem that has plagued them all season.
Oakland has scored just 64 runs in 22 games -- the fewest in franchise history over that many games. One bright spot was Coco Crisp, who picked up two more hits after missing seven of the past eight games prior to this series with an ear infection. He also extended his streak of successful steal attempts to 27 -- the second longest in A's history.
Orioles' left-hander Wei-Yin Chen kept the A's off balance all night with his four-seam fastball and slider. He allowed one run on six hits with four strikeouts and two walks over seven innings -- the longest outing of his young career.
"I don't think he overpowered us. I think we just missed him a lot," said left fielder Josh Reddick, who went 1-for-4. "In my first at-bat, I missed two pitches I should have hit really well. I felt like I missed a lot of fastballs."
Baltimore took the lead with a five-run second inning on six singles. Catcher Ronny Paulino had two RBIs, and Chris Davis and Robert Andino each had one. J.J. Hardy added the fifth run on a sacrifice fly. An errant pickoff throw by catcher Kurt Suzuki advanced runners to second and third, and each eventually scored.
"We're trying to do too much at times," manager Bob Melvin said. "When there's big innings, we're trying to make the great throw, or we're trying to throw to a base when maybe we should just get the ball in and keep the double play in order. It was a slick, wet ball, but the other team has to field them, too, and we were not as good as them tonight."
An RBI double in third by Wilson Betemit increased the lead to six runs.
After loading the bases in the first inning, the A's didn't threaten to put together another big inning.
"We had our opportunities, especially in the first two innings," Melvin said. "After that first inning, it felt like it was a momentum swing. They got out of it, and we could not muster anything after that."
Adam Jones' RBI single ended Ross' night in the fifth with no outs. Reliever Jerry Blevins entered and allowed a two-run single to Davis, with both runs charged to Ross.
The A's got the board on a home run by Jonny Gomes in the sixth. Gomes is now second on the team in homers, with four, behind Yoenis Cespedes, who has five.
Jim Miller, the A's fourth pitcher of the night, allowed a 418-foot homer to Davis in the seventh. It was the 59th ball to reach Eutaw Street in Camden Yards' 20-year history.
Davis went 3-for-4 with four RBIs.
Todd Karpovich is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.