"With Chacin's command of his pitches, we thought that would be a better setup for us to deal with," Mills said. "We saw Vlad hit a ball four or five inches outside and find a hole. It was a situation where I thought we needed to get the matchup we needed in that situation."
The Rangers, who swept the three-game series and beat the Astros for the eighth time in nine games, scored the tying run off Houston closer Matt Lindstrom in the ninth before Borbon led off the 10th with a single off reliever Casey Daigle and scored on Hamilton's career-high-tying fifth hit of the game.
"Any loss is tough, especially when they come out and get the first two games," shortstop Tommy Manzella said. "You're going to try to scrap and do whatever you can to get that third one. We had our situation there. You have to give credit to them. They came back and battled in the ninth and did what they had to do to drive the run in."
The Astros have now lost eight of nine games to fall to a season-low 18 games under .500 (26-44). Following the game, the club shook up its roster, purchasing the contract of No. 1 prospect Jason Castro and anointing him the starting catcher. Rookie third baseman Chris Johnson and outfielder Jason Bourgeois were also added from Triple-A Round Rock.
"I think we have to see what some of these guys can do," Mills said. "If they are the ones to go further, to go beyond this year, then we need to find those answers, and we need to find out about it."
The Astros were outhit, 15-7, on Sunday by the Rangers, who stranded 16 runners on base. Hamilton extended his hitting streak to a career-high 16 games by going 5-for-6, tying his career high of five hits, set in 2008 against the Astros.
"Texas has a good lineup," said starter Felipe Paulino, who gave up 10 hits and three runs (two earned) in six innings. "I'm not afraid of that. I just went out there like I pitched before, and tried to go out there and make a good pitch and put the ball in play."
Paulino and the Astros had a three-run lead after three innings before the Rangers chipped away. Texas had cut the lead to one run heading into the ninth and rallied against Lindstrom, who blew his fourth save of the season by allowing Hamilton's game-tying RBI single.
"They were aggressive," Lindstrom said. "It seemed like I was fighting myself a little bit out there. Normally, my control is not that bad, but today is one of those days I was almost thinking one thing and it was doing another.
"I was trying to battle out there, but I was out there scratching my head, too, because there were pitches I wanted to throw and I thought I could throw with location, and they seemed to go the other way. I was fighting myself and didn't get the job done. I've got to get better next time. I just feel bad about letting the guys down. Paulino pitched great. It's frustration, for sure. "
Lindstrom wound up escaping a bases-loaded jam in the ninth to keep the deficit at one run, but Daigle gave up a lead-off single to Borbon in the 10th. Borbon was at second base with two outs when Mills opted to walk Guerrero (0-for-5) and bring in Chacin to face the left-handed Hamilton, who laced a 2-1 pitch into right field to score Borbon, who went 4-for-5 with a walk.
"The way Josh is swinging right now, it doesn't matter who is out here," Rangers manager Ron Washington said. "He's not trying to do too much. Chacin threw one down and away, and he stayed on it. He got a single. That's all we needed."
The Astros got RBIs from Lance Berkman and Carlos Lee in the first inning, and took advantage of a fielding error by Guerrero in right field in the second to score a pair of unearned runs against C.J. Wilson and take a three-run lead.