By winning the final two games of the set, the Astros won their first Lone Star Series against the Rangers since June 2008, which was also the last time they beat the Rangers twice in a row. The Rangers had won the 15 previous series against Houston.
"I had no idea it had been that long," said Feldman, who started for the Astros and gave up four runs on 10 hits in five innings.
The Astros rallied from four runs down for their biggest come-from-behind win of the season. George Springer tied it at 4-4 in the seventh inning with a two-run homer, and Houston's beleaguered bullpen stepped up and threw four scoreless innings, with Chad Qualls (1-1) getting the win.
"They just got us," Rangers manager Ron Washington said. "That's all I can say. It just got away from us. I'm man enough to say they just beat us."
The Astros had exactly 11 hits -- tying a season high for the eighth time -- for the fifth consecutive game, which is the first time they've done that in franchise history. Dexter Fowler went 3-for-3 with two walks, Jason Castro was 2-for-3 with two walks and Dominguez was 2-for-5.
"From the dominance they've shown against us here lately, it's definitely something to be proud of," Astros manager Bo Porter said. "I'm proud of the men in that room in there for the way they battled today. If last night was our biggest win and had our best individual performance in [Dallas] Keuchel, I think tonight was our biggest win as far as team performance goes."
The most the Astros had trailed by in any win this season was two runs.
"When these guys continue to battle the way they battle, and I know sometimes they come up short, but as we sit there as a staff we always feel like we're one hit away," Porter said. "Tonight we were able to get those hits."
The Rangers built their four-run lead behind starter Nick Tepesch, who gave up one run on two hits in 5 1/3 innings. The Astros cut the lead in half in the sixth with bases-loaded RBI singles by Jesus Guzman and Chris Carter, and Springer tied the game in the seventh with a screaming line drive into the Crawford Boxes in left field.
"I was looking for something to hit," said Springer, whose homer was his first at Minute Maid Park. "I wasn't trying to hit a home run, but ended up hitting one. It's obviously big for me as a player, but also to help the team tie it up and give us a spark, I guess."
Darin Downs, Paul Clemens, Tony Sipp and Qualls combined to hold the Rangers scoreless on one hit over the final four innings. Sipp retired five straight, including three by strikeout. He's set down all 17 batters he's faced (10 by strikeout) since signing with the Astros.
"I don't feel unhittable," he said. "I've been on both sides before. One day you have everything, and the next day you feel you can't get a strike across the plate. Baseball is more about momentum, and right now momentum is going in the right direction and we're trying to keep it there."
Fowler started the ninth with a one-out single, and Castro followed with a walk. Dominguez hammered a 3-2 pitch from Nick Martinez (0-1) and sent it to the wall in right-center field, allowing Fowler to score easily.
It's the second walk-off win for the Astros and the first walk-off hit for Dominguez, who has two hits in five of his last six games.
"I was looking for a fastball over the plate and wasn't trying to do too much and just try to hit a line drive somewhere and got to 3-2 and got a fastball," Dominguez said.
Feldman, facing his former team for the second time this season, had nothing come easy following a 1-2-3 first inning.
Alex Rios hit a solo homer in the second, and Prince Fielder hit an RBI single in the third into the teeth of the Astros' shift to make it 2-0. An RBI single by Adrian Beltre and an RBI double by Fielder in the fifth made it 4-0.
"It was just a battle for me," Feldman said. "It's kind of frustrating a little bit, but I kept the team in the game as well as I could. I would have liked to have gone deeper in the game, but we ended up with the win, so that's the main thing."