BALTIMORE -- The game didn't get strange for Baltimore's Bud Norris until around the fourth inning when he glanced over at the Houston dugout and saw a bunch of former teammates he was now trying to beat.
Norris earned the win in his debut for the Orioles and Chris Davis got his league-leading 39th home run as Baltimore topped the Astros, 6-3, on Thursday night.
With the victory, Baltimore took the three-game series. The Orioles also stayed 5.5 games behind the first place Red Sox, who scored six runs in the bottom of the ninth to beat Seattle 8-7.
Norris (1-0), who was traded by the Astros the previous day, allowed two runs on four hits with a season-high eight strikeouts and two walks in six innings. He also picked up his 14th quality start in 22 games this season.
"As an Oriole, it's pretty special," Norris said. "I've been working a long time in my career to be in a pennant race, and this is exactly what it is. To be thrown in the fire, and go out there and control my emotions was pretty special."
Nate McLouth went 2-for-4 with 2 RBI for the Orioles. Rookie Henry Urrutia, Manny Machado and Davis also had two hits each for Baltimore. Orioles closer Jim Johnson picked up his 37th save with a scoreless ninth.
Houston starter Jordan Lyles (4-5) took the loss and allowed five runs (three earned) on nine hits with five strikeouts and no walks in 5 2/3 innings.
Astros manager Bo Porter stacked the lineup with three lefties and three switch hitters against Norris. The strategy initially worked as Jason Castro and Marc Krauss each homered. Norris has given up 12 homers to left-handed hitters and just one to a righty this season.
The Orioles opened a 4-2 lead in the sixth on a two-out, RBI single by Brian Roberts that ended Norris' night. Travis Blackley entered and immediately allowed another RBI single to McLouth. Davis then provided more cushion with a mammoth shot to right off Blackley in the seventh.
"They obviously knew plenty about [Norris] and had seen plenty of him, so to go out and compete the way he did was huge," Davis said. "That's what we expect out of him, to eat up innings and keep us in the ballgame."
L.J. Hoes, who was traded by Baltimore for Norris, pulled the Astros to within 6-3 with his first Major League RBI on a grounder in the eighth.
Wallace gave the Astros a 1-0 lead when he greeted Norris with a long home run to right-center in the second.
"Obviously knowing him a little bit, and growing up playing against him, it's fun," Wallace said about Norris. "We're definitely competitive against each other. It felt good, but we were more worried about getting the win and that's what we were focused on."
Krauss increased the margin to 2-0 with a two-out, solo homer in the fourth. Norris had given up just two home runs in three of his past 21 starts with the Astros, but he equalled that number in four innings against his former team.
"He's going to get the ball and hopefully can help us get where we want to get," Orioles manager Buck Showalter said about Norris. "We gave up some good people for him and we think we got somebody back good."
A single by Nate McLouth cut the lead to 2-1 in the fifth and ended a 15-inning scoreless streak by the Orioles. Manny Machado tied the game one batter later with a single and Nick Markakis provided the lead with a sacrifice fly.
"He was typical Bud Norris," Porter said. "Great command. He pitched to both sides of the plate. I thought he did a really good job throwing good sliders in some hitters counts and kind of took advantage of a little bit of over-aggressiveness by our guys."
NOTES: Astros manager Bo Porter set his rotation Thursday for the weekend series against Minnesota, going in order with rookie RHP Jarred Cosart, LHP Erik Bedard and LHP Dallas Keuchel. ... The Astros recalled 2B Jimmy Paredes from Triple-A affiliate Oklahoma City, and he started at second base in place of Jose Altuve, who has a left quad strain. ... Orioles RHP Jason Hammel, who was placed on the disabled list Monday with right flexor mass tightness, is scheduled to have an MRI on Friday. ... Orioles 3B Manny Machado snapped an 0-for-14 skid with a single in the first inning.