"That's what baseball is about -- momentum," Ian Kinsler said. "We tried to come back, tried to put some runs on the board, but we didn't."
Michael Young homered to right field with one out in the bottom of the first, and Chris Davis went deep an inning later to put the Rangers ahead, 2-0.
The Rangers have now hit 12 consecutive solo home runs. That matches the longest stretch in club history, last set by the 1986 squad from Sept. 6-13.
Young is carrying a .404 batting average (19-for-47) with eight RBIs over his 11-game hit streak in Interleague games. He has also hit in 26 of his last 31 games against the Astros, posting a .352 (45-for-128) batting average with five home runs.
Davis' home run, his first since going deep May 26 against the Yankees, snapped a personal 17-game drought.
The circumstances seemed ripe for the Rangers to continue their long ball stroke. Brandon Backe, the Astros' starter, led the National League in home runs allowed last season, and the Rangers entered the game with the second-most home runs in the Majors this season.
The Rangers would score only once more. In the fourth inning, Nelson Cruz singled with one out and advanced to second on a single by David Murphy. Cruz then stole second and scored on a throwing error by catcher Humberto Quintero to make it 3-0.
From there, momentum swung in favor of the Astros.
With two outs in the fifth inning, Darin Erstad doubled and scored on a single by Quintero. It was Erstad's first hit in 28 at-bats. Rangers starter Vicente Padilla responded by inducing a groundout to second base to finish the inning, but a 36-pitch sixth inning would be his undoing.
Jeff Keppinger walked to lead off the inning, and Miguel Tejada followed with a single. Carlos Lee drove home Keppinger with a single, and Tejada scored on a passed ball by Rangers catcher Taylor Teagarden.
Padilla then struck out Pence before allowing a single to Kazuo Matsui to load the bases. He then fanned Darin Erstad and got Quintero to ground into a fielder's choice to end the inning.
"They came out and worked Padilla hard," Rangers manager Ron Washington said. "He still came out with a tie ballgame, but it felt like the momentum changed. We still came out of the sixth with a tie."
Padilla had difficulty escaping the first inning again Thursday, needing 28 pitches. In his last start Saturday against the Dodgers, Padilla was forced to throw 29 pitches to escape the opening frame.
But Padilla recorded his sixth quality start of the season and is tied with Scott Feldman for second-most on the staff. Over his last eight outings, Padilla has a 3.38 ERA, which has lowered his season ERA from 8.27 to 4.79.
Padilla has also completed at least six full innings in seven of his last nine starts after averaging 4 2/3 innings over his first three outings this season. The Rangers fell to 8-4 in games started by Padilla this season.
Jason Jennings pitched a scoreless seventh but allowed Pence's solo home run and an RBI triple to Astros leadoff hitter Michael Bourn in the eighth inning. Those two runs put the Astros ahead for good and gave Jennings the loss.
"To win today was important," Pence said. "We took care of business today. They're a good ballclub and they had our number, so it feels good to get a win."
Alberto Arias pitched one-third of an inning for the win, the third of his career.
The Rangers finished their nine-game homestand 4-5 with one game against the Blue Jays postponed. They are 6-3 in Interleague games this season and finished the season series against the Astros 5-1.