AP Sports Writer
BALTIMORE (AP) -- Nate McLouth was at a loss to explain the Baltimore Orioles' dud of a performance against a team with the poorest record in the majors.
"That was kind of baffling. Pretty safe to say that was our worst game of the year," the outfielder said after the Orioles absorbed an 11-0 beating from the Houston Astros on Wednesday night. "It was embarrassing, actually. I'm glad it's over."
Going up against a rookie who found out only hours earlier that he was going to receive his first major league start, Baltimore managed only three singles in seven innings off Brett Oberholtzer.
Oberholtzer (1-0) was thrust into the starter's role after Erik Bedard was scratched with a sore shoulder. Making his fourth appearance and first start in the big leagues, Oberholtzer struck out six, walked none and did not let a runner get past first base in earning his first win in the big leagues.
"He threw strikes and he had a lead," Baltimore's Adam Jones said. "Tip your cap to him, man."
The Astros build a 9-0 advantage over four innings against Orioles starter Miguel Gonzalez (8-5) and coasted to their most lopsided win of the season.
"My bullpen was great, everything was down, and I thought I was going to go out there and do pretty well," Gonzalez said. "The first inning was good, second inning I was just leaving the ball up, and it just carried on throughout the whole game. It was just a tough night for me overall."
And for the Orioles.
It was Baltimore's worst margin of defeat this year, and the second time in three games the Orioles absorbed a shutout. Prior to that, they had been blanked three times in 105 games.
Baltimore finished with seven hits, two apiece in the eighth and ninth innings.
"We haven't swung the bats real well as of late. Kind of collectively," manager Buck Showalter said. "You don't say that's just one of those things that's going to happen. You want to shorten it up and get back to what we're capable of. Tomorrow's an opportunity to do that."
The Orioles can only hope the feeling they got from this game doesn't languish.
"It shows you, you just never know what you're going to get on a given night," McLouth said. "Our fans don't deserve to see that type of performance. We'll clean that up. We'll have to get over that one quick."
Hours before the first pitch, the Astros traded right-hander Bud Norris to the Orioles for outfielder L.J. Hoes and a minor league prospect. Hoes switched from the Baltimore starting lineup to batting second for Houston and went 0 for 5.
Norris, the focal point of the trade, will start the deciding game of the series Thursday night against his former teammates.
In this one, Matt Dominguez homered and had a career-high four hits to help the Astros improve to 3-9 since the All-Star break.
"It all started on the mound with Oberholtzer," manager Bo Porter said. "What a tremendous job. It's amazing what happens when you throw strikes and don't put people on base."
Houston took control with a four-run second. After Castro hit a leadoff double, Brandon Barnes delivered an RBI double and scored on a single by Dominguez before Robbie Grossman hit a shot onto Eutaw Street beyond the right-field scoreboard.
The Astros tacked on five runs in the fourth, courtesy of a botched grounder by shortstop J.J. Hardy. The two-out miscue with the bases loaded allowed a run to score, and Castro followed with his first career grand slam.
Brett Wallace hit an RBI single in the sixth and Dominguez homered off Francisco Rodriguez leading off the seventh.
NOTES: The Orioles put RHP Jason Hammel (strained flexor muscle) on the 15-day disabled list and activated Steve Pearce from the DL. ... Orioles star Chris Davis extended his club-record run of games with a strikeout to 24. ... Porter said Bedard was scratched "to give him a couple extra days of rest."
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