Moehler (6-4) cruised through eight innings and had a remarkably low pitch count heading into the final frame, giving him reason to believe he was going the distance. But Jeff Keppinger led off the ninth with a double, and after Adam Dunn flew out to deep right, Keppinger scored on Brandon Phillips' groundout to third.
Still, Moehler's chances to stay in the game were relatively good -- that is, until Jay Bruce singled to center and pinch-hitter Javier Valentin walked. At that point, Cooper didn't hesitate as he popped out of the dugout to call for Wright.
"It was disappointing, no doubt about it," Moehler said. "Especially a 6-1 lead and not be able to finish a game. But I understand Coop's decision. I walked [Valentin], and they're one hitter away from loading up the bases and one pitch away from tying the game. I have no problem with the decision."
As Wright jogged in from the bullpen, he heard Astros fans booing Cooper for lifting the starting pitcher.
"When I came in, I was like, 'Well, this is definitely not a situation I want to mess up,'" said Wright, who struck out Joey Votto to log his first career save. "I wanted to get him out, and everything worked out."
Moehler's outing was his longest since August 8, 2000, when he threw a complete game against the Orioles as a member of the Tigers' pitching staff. He has won two straight decisions for the first time since August 2006.
He also has the second-lowest ERA of all of the Astros' starters, behind only Wandy Rodriguez. Not a bad resume for a 36-year-old veteran who had to make the team out of Spring Training and started the season as a seldom-used reliever.
"It lets me know the guy has what it takes," Cooper said. "He's really worked hard to get an opportunity and he's taken advantage of it. Moe's been around a while. He got new life, so to speak, and he's taken advantage of it. This guy works extremely hard every day."
The game was close until the fifth, when Carlos Lee knocked his 12th career grand slam off Bronson Arroyo to turn a one-run lead into a much more comfortable 6-1 advantage.
Lee's slam -- along with a small rally that loaded the bases for the slugger -- arrived with two outs. Kazuo Matsui took two called strikes before fouling off six of the next eight pitches, and he capped the 11-pitch at-bat with a base hit up the middle.
Miguel Tejada followed with a base hit, also to center, before Arroyo (9-8) hit Lance Berkman in the upper arm, loading the bases. Lee unloaded them with his 24th homer of the year.
"The two at-bats before, [Arroyo] was trying to throw sinkers in, and I kept fouling it off," Lee said. "He was getting me out that way, so I guess since he had success with it, he was going to try to do it again. I was ready for it."
Lee provided the drama, but Matsui's at-bat didn't go unnoticed either.
"Kaz's at-bat before the grand slam was as good as any," Cooper said. "Down 0-2, he fouled off seven, eight, nine pitches and gets a base hit. That's clutch hitting. That's what it's all about."
After Lee's slam, Moehler had a feeling he'd go deep in the game.
"It gives you a little breathing room," he said. "You tend to go after guys a little more. That was huge."
It also helped that the Reds were swinging early and often.
"Anytime you get up 6-1, you know the team's going to come out and be a little more aggressive because they know you're going to start pumping fastballs in there," Moehler said. "The last thing you want to do is walk guys with a 6-1 lead. They were aggressive, and they popped some balls up and got some first-pitch outs. At the same time, they got some hits late in the game and made it interesting."
Where the Astros (50-56) finish in the National League Central standings remains to be seen, but they took one small step in the right direction against the Reds (50-58) on Tuesday, taking over fourth place. It's a modest accomplishment, but one that should be noted considering that's the highest the Astros have been in the standings in nearly a month.
"We're doing a lot better job trying to get on base and create some situations, put some people in scoring position," Lee said. "Kaz is doing really good. Miggy, in the second spot, he's come on, getting on base, even walking. That's what we needed -- create situations and give us opportunities to score runs."