Adrian Beltre clubbed the go-ahead two-run homer in the sixth inning and the Texas Rangers edged Houston, 4-2, to continue their domination of the Astros.
Travis Blackley, who was acquired from Houston in exchange for cash considerations on Aug. 14 after being designated for assignment by the Astros, allowed three hits and two runs over four innings in his Rangers debut.
Neal Cotts (5-2) had three strikeouts in 1 1/3 innings of relief for the AL West leaders, who have won 17 of their last 21 games overall. The Rangers have also beaten the Astros in 13 of the last 14 meetings.
Joe Nathan struck out the side in the ninth to pick up his 37th save.
Jarred Cosart (1-1) gave up more than two runs for the first time in his career. The right-hander, in his seventh major league start, allowed four hits and three runs over six innings.
"I was keeping them off balance," Cosart said. "A couple of guys buckled on curveballs. I threw it for a strike and they couldn't sit on one pitch. That helped me get through six, but Beltre kind of speaks for itself."
The Astros, who lost 16-5 on Monday in the opener of this three-game set, secured the early lead. Matt Dominguez belted a homer to left field with Chris Carter aboard in the second inning.
Beltre doubled to start the bottom half of the frame and scored on an Alex Rios single to third base.
Ian Kinsler walked with one out in the sixth and Beltre turned on a 1-1 pitch and homered to right field for the 3-2 lead.
"I'm getting lucky," Beltre said of his recent hot hitting that has seen him log 20 RBI since July 30.
Texas loaded the bases in the eighth before Elvis Andrus scored on a Josh Zeid wild pitch.