OAKLAND, Calif. — The Orioles rotation continued to do its part Thursday, and the club's offense finally followed suit.

Right-hander Chris Tillman provided the team's seventh straight quality start, and he received plenty of run support in a 9-6 win over the Oakland Athletics as the Orioles avoided their first four-game sweep in Oakland since 2004.

Tillman, making his fourth attempt to win his 15th game of the season, held the Athletics to two runs over seven innings, making an early 7-0 lead hold.

“Same [as] we've seen all year, just a bulldog,” said right fielder Mark Trumbo, who hit a grand slam and drove in five runs.

Tillman held the A's scoreless through 41/3 innings, retiring 13 of the first 16 batters he faced before allowing a two-run homer to third baseman Ryon Healy. Tillman (15-4) retired eight of the final nine batters he faced.

Catcher Matt Wieters “did a good job once again, never really giving in to the count,” Tillman said. “We used all our pitches in all the counts, never backed ourselves in the corner. For the most part, we were one step ahead.”

Healy's homer was the only extra-base hit Tillman allowed.

Tillman has allowed three runs or fewer in seven of his past eight starts, with a 2.96 ERA over that stretch. He has gone seven innings in five of his past eight starts.

Over the streak of quality starts, the rotation has a 2.93?ERA but is just 3-4 in those games, in part because the team was going through an ugly stretch at the plate. The Orioles scored just three runs over their first three games in Oakland.

Bullpen shows holes: Right-handed reliever Logan Ondrusek, who was signed because of his success against left-handed hitters, allowed a solo homer to left-handed-hitting Max Muncy in the eighth. Three of the four batters Ondrusek faced reached base as he walked switch-hitter Coco Crisp and left-hander Stephen Vogt. Marcus Semien hit into a double play in between the bases on balls.

Left-handers are 4-for-8 with three extra-base hits (two doubles, one homer) and two walks off Ondrusek.

Ondrusek was optioned to Double-A Bowie after Thursday's game. Left-hander Donnie Hart will join the Orioles in San Francisco.

Darren O'Day struggled to get out of the inning in relief of Ondrusek. He walked former Oriole Danny Valencia and allowed a two-run double to Yonder Alonso to end a nine-pitch at bat. Billy Butler followed with an RBI single to cut the lead to 9-6.

O'Day, who was charged with two runs in one-third of an inning, has allowed five runs in 12/3 innings over his past three outings.

“He wasn't able to finish off some things that he normally finishes off,” manager Buck Showalter said. “He's a little frustrated right now. We'll see if everything's OK.”

Britton dodges damage in ninth: Despite loading the bases in the ninth and bringing the potential winning run to the plate, closer Zach Britton pitched a scoreless inning to remain perfect on the season by converting his 35th straight save opportunity.

eencina@baltsun.com

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