HOUSTON (AP) -- Baltimore starter Chris Tillman swears he enjoys pitching at Camden Yards. With the success he's had away from there this season, he might be starting to hope his spot in the rotation always comes up on the road.
Tillman threw seven solid innings and the Orioles ended Houston's six-game winning streak with a 4-1 win over the Astros on Tuesday night.
Tillman (5-3) allowed four hits and a run and tied a career-high with eight strikeouts in seven innings to improve to 4-0 with a 2.30 ERA on the road. He bounced back from his last start where he was tagged for a career-worst four home runs against the Nationals.
He was at a loss as to explain why he's been so good on the road.
''I can't put my finger on it,'' he said. ''I go out with the same game plan every time and try to do my best every time.''
Teammate Adam Jones has been impressed with Tillman's development.
''He's learning to calm down that crowd,'' Jones said. ''Even when they get rallies, he's learning to take that extra second to gather himself and just to quiet the crowd down and the man is going out there and making good pitches. I've been around Tillman for the past six or seven years and he's starting to really come into his own at this level and it's just good to see.''
The 24-year-old Tillman's eight strikeouts were the most he's had since Sept. 11 2009.
''He's still young,'' manager Buck Showalter said. ''I think this is his 63rd start in the big leagues. That's infant stage for starters. Chris has matured into a guy that on a given night you can really count on.''
Jim Johnson struck out two in a scoreless ninth for his 19th save.
Brandon Barnes had a solo homer in the sixth for the Astros, who entered the game with the longest winning streak in the majors.
Houston starter Lucas Harrell (4-7) yielded five hits and two runs - one earned - with a season-high six strikeouts in seven innings.
''Lucas had some things that he needed to straighten out, and it was a learning experience for him,'' manager Bo Porter said. ''He's more composed, things don't snowball the way they did earlier in the season, and that's a credit to him for taking constructive criticism and making adjustments.''
The loss ends a surprising week for the Astros where they had a perfect road trip by winning a two-game series with Colorado before a four-game sweep of the Angels.
Danny Valencia led off the third inning with a home run to the first row of the seats in right field to give Baltimore a 1-0 lead. It was the third home run of the season for Valencia in just his ninth game. He hit three home runs in 44 games last season.
''The more you're in there, the more you feel comfortable and you get your results and you feel better and better and better,'' he said. ''Hopefully I can just contribute when I'm in the lineup.''
Manny Machado hit a one-out double before advancing to third on a wild pitch with two outs. Machado scored on an error by first baseman Chris Carter on a grounder by Adam Jones that allowed him to reach and put the Orioles ahead 2-0.
Harrell sat down 13 of the next 14 of the next batters he faced after the error, with the only hit coming on a single with two outs in the fourth inning.
Wesley Wright took over for the eighth inning and was greeted with a single by Nate McLouth. He stole second base before swiping third with one out and scoring on that play on an error by catcher Jason Castro when he overthrew third base.
Tillman plunked Carlos Pena to start the second inning before retiring nine in a row, including striking out the side in the third. He walked Carter to start the fifth, but still faced the minimum in that inning when Matt Dominguez grounded into a double play with one out.
Barnes got Houston within one with his solo homer to the Crawford Boxes with one out in the sixth inning.
Jimmy Paredes hit a two-out single in the seventh inning and stole second base. Tillman ended the threat when he battled with Dominguez before striking him out on the 10th pitch of the at-bat.
Barnes, the center fielder, robbed Machado of a hit when he made a diving catch on a fly ball with one out in the fifth inning. Jones also made a nifty catch in center field when he snagged a liner by Jose Altuve over his shoulder while in a full sprint to end the eighth inning.
''I thought we had some pretty good at-bats,'' Porter said. ''It just seemed like when we were hitting the ball hard, Adam Jones was running up Tal's Hill and making great plays.''
NOTES: The series continues on Wednesday when Baltimore's Freddy Garcia opposes Dallas Keuchel. ... The Astros are wearing special patches during this series to honor the four firefighters who were killed battling a Houston motel and restaurant fire last week. The patches are black with ''HFD'' written in white block letters on them. More than a dozen other firefighters were hospitalized after Friday's blaze, the deadliest in the 118-year history of the department. ... Baltimore RF Nick Markakis will miss Wednesday and Thursday's games to attend the funeral of his grandmother. Orioles manager Buck Showalter said he won't go on the bereavement list because he will be back for Friday's game against Tampa Bay.