"That's how you play the game," Myers said. "We played the game hard. We've had a lot of one-run games we've lost, but hopefully those games have made us better to win some of these one-run games."
Astros starter Bud Norris (3-1) pitched six scoreless innings, escaping a bases-loaded, no-out jam in the sixth inning, and the bullpen took it from there. Wesley Wright threw two-thirds of an inning, Wilton Lopez threw 1 1/3 scoreless innings and Myers slammed the door with a 1-2-3 ninth.
"The Regulators mounted up," Myers said, referring to the bullpen's moniker.
Houston -- now 6-6 in one-run games -- has won seven of its last 10 games overall and has moved into sole possession of third place in the National League Central.
"That was a great team win, and Bud obviously did a great job of keeping them down all game and really getting out of some big spots," shortstop Jed Lowrie said. "They had some opportunities to score and Bud made pitches when he needed to."
After cruising through five innings, in which he faced only 15 batters and allowed one batter to reach base, Norris got into huge trouble in the sixth by allowing a pair of hits and then making a fielding error on a bunt by pitcher James McDonald.
"I was a little upset with myself," Norris said. "I was worried about the runner going home. I definitely just missed it. It was my own fault and I was trying to get the out at first, but it was too late. It ended up [that it] didn't hurt me and I got out of the jam."
That's because Norris struck out Jose Tabata on a 3-2 pitch, got Nate McLouth to pop out to second on a 3-2 pitch and then struck out Andrew McCutchen on a 3-2 pitch to escape the jam. He threw 33 of his 94 pitches in the sixth inning.
"He knows he's got enough good stuff to work through that, and he did for the second time in a row," Mills said of Norris, who escaped a late-inning jam in his previous start. "We wish he wouldn't have to go through it like that, but at the same time, it's good to see him battle and tighten the screws a little bit."
Pirates manager Clint Hurdle didn't think his players got over-anxious.
"When the game gets hard, it looks more difficult to play than it is," Hurdle said.
The only run the Astros scored came on a double play ball in the second. Brian Bogusevic and Chris Johnson (2-for-3) began the inning with consecutive singles, with Bogusevic going from first to third to put himself in position to score on Justin Maxwell's 5-4-3 double play.
"When we talk about little things, those are the things we have to do, because we're not always going to score a ton of runs," Bogusevic said. "Going first to third and bunts can add up to runs, and today it was what we needed. Mills wants us to be aggressive and it paid off."
Norris sent down the first nine batters before Tabata led off the fourth inning with a triple. But he was cut down at the plate one out later on a terrific throw by Lowrie to catcher Jason Castro, who made the tag.
"We started back and crept in right before the pitch, and that was the idea, to get the out at the plate and hopefully get the ground ball," Lowrie said. "He was able to do that."
Mills was tossed by Joyce for arguing a controversial play in the eighth. A pitch glanced off the bat of Pirates shortstop Clint Barmes and dribbled foul while he was trying to pull back on a bunt attempt. The umpires originally said he was out before huddling and calling Barmes back to the box.
"I was contending that he was still bunting, and the umpires felt no, he pulled it back and he wasn't bunting," Mills said. "Obviously, we had a disagreement. And that was it."