BALTIMORE -- Brett Oberholtzer served as a fill-in starter for the Houston Astros on Wednesday night, stepping in for Erik Bedard. The rookie left-hander was making his first major league start, but he looked a lot like an accomplished veteran.
Jason Castro hit a grand slam while Matt Dominguez and Robbie Grossman also homered to help back up Oberholtzer's seven shutout innings as the Astros rolled to an 11-0 victory over the Baltimore Orioles on Wednesday night at Camden Yards.
Oberholtzer (1-0) gave up only three hits, striking out six without a walk, something that delighted Houston manager Bo Porter, especially after walks hurt Houston badly in Tuesday's loss.
"I think it (all) started on the mound with Oberholtzer," Porter said. "What a tremendous job. He did a great job of attacking the strike zone."
But Oberholtzer relaxed because the Astros (36-70) scored four runs in the second for a quick early lead.
"We did a great job getting a four-spot in the second inning," he said. "I just thought to myself 'that's a start right there. Now it's time to go out and throw strikes.'"
He did just that and the offense helped him out on a night of firsts for the young Houston team. Castro's first career grand slam broke the game open as part of a five-run fourth which gave Houston a 9-0 lead. He finished 3-for-4 with those four RBIs.
Dominguez hit a solo homer in the seventh as part of his 4-for-5 night with two RBIs as he had a run-scoring single earlier. Grossman (2-for-4, two RBIs) added a two-run homer as part of a four-run third, and that was his first major league homer.
"The last few games we've done a good job of scoring runs early. But in order for us to really kind of get the wheels moving I think what we did tonight was a great start, kind of adding on and taking advantage of some opportunities," Castro said. "That's what we need to do. It was good to see."
Adding to the night of firsts for Houston, right-hander Chia-Jen Lo made his major league debut when he replaced Oberholtzer in the eighth. Lo threw a scoreless eighth.
Baltimore (59-49) finished with seven hits, five of which came in the last three innings, but the Orioles couldn't score.
The Orioles and Astros completed a trade before the game. Baltimore acquired starting pitcher Bud Norris from Houston in exchange for outfielder L.J. Hoes and minor league pitcher Josh Hader.
Norris had been scheduled to start Monday night's series opener, but was scratched. In addition, Hoes was originally in Baltimore's starting lineup for this game but went over to the Astros and joined their lineup, batting second and playing right field. He went 0-for-5 and also moved to center later in the game.
For the second straight night, Houston took an early lead. This time, the Astros scored four runs in the second inning against Orioles starter Miguel Gonzalez (8-5) and never looked back.
Brandon Barnes drove in the first run with a two-out RBI double. Matt Dominguez followed with an RBI single up the middle, and Grossman then blasted his two-run homer inside the right-field foul pole for a quick 4-0 edge.
But unlike Tuesday, the Astros took control after that. They broke it open with the five-run fourth inning for a 9-0 lead.
Gonzalez nearly got out of the inning unscathed, but shortstop J.J. Hardy booted Jose Altuve's two-out grounder that would have ended the fourth. The right-hander needed just five pitches to get through the first inning but everything came apart after that. He lasted just 3 2/3 innings (a season low) and gave up nine runs on nine hits.
"I was surprised," Orioles manager Buck Showalter said. "I thought he'd be a little better tonight. He wasn't. Breaking ball wasn't very crisp and command of his fastball was an issue for him most of the night. Very unlike Miguel. He'll be better next time out."
NOTES: Manny Machado (third base) and Hardy (shortstop) have started 148 consecutive games together on the left side since Aug. 21, 2012. ... Jim Johnson now has 108 career saves, which ranks second in Orioles club history, behind only Gregg Olson (160). ... The Astros now have scratched their original starters in each of the first two games of this series. ... This victory was Houston's first in Baltimore. The Astros came into this game with an 0-7 record at Camden Yards.