With the Cardinals' loss on Sunday, the Reds lead the National League Central by a season-high 9 1/2 games with 27 to go.
"That was a huge comeback for us," starter Bronson Arroyo said. "This is a team we should beat. We didn't want to end a road trip losing a series to a team you took Game 1 from, and [we] felt like we should've beat these guys anyway."
Reds manager Dusty Baker said things looked grim after the Reds failed to score in the sixth against starter Bud Norris.
"You're like 'Oh no,' because we didn't have a whole bunch of chances," Baker said. "That was our big chance."
Well, the Reds got another big chance. Bruce took advantage this time, hitting his 29th homer of the season and 11th off left-handed pitching.
"The Reds are the best team in the National League, and teams like that are going to do that, they're going to keep pushing all the way to the last out," Astros shortstop Tyler Greene said.
Bruce wasn't necessarily looking to jump on the first pitch.
"I was just trying to get a good pitch to hit, get a ball I could handle," Bruce said. "I think most people try to get me out down, out of the zone. I just tried to really stay away from that and get something I could hit."
Bruce, from nearby Beaumont, Texas, won't get a chance to play in front of family and friends as much next year when the Astros move to the American League West. He's had success at Minute Maid Park: a .288 average with eight homers and 23 RBIs in 38 games.
"I made the best of it while it lasted," Bruce said.
The Reds' comeback helped Arroyo avoid the loss after a strong six innings on the mound.
Arroyo, who registered the rotation's sixth consecutive quality start, motored through the first four innings, facing the minimum and only allowing a double in the third to Brian Bogusevic, who was caught stealing on the next pitch.
The Astros plated a run in the fifth on Bogusevic's RBI forceout.
Arroyo retired the side in order in the sixth and was pinch-hit for by Henry Rodriguez with two outs and a runner on first in the seventh. The right-hander threw 75 pitches and allowed one run on three hits.
Arroyo didn't want to leave the game after six with a low pitch count, and Baker didn't want to take him out, but with the Reds trailing by a run, Baker decided he needed as much offense as he could get.
"That was that point where we had to get some runs," Baker said. "Most rallies are started with two outs. We were banking on that, but it didn't happen."
A silver lining for Arroyo: maybe his arm will feel fresher the next time he pitches.
"I've racked up a lot of innings, and having a blow like that, especially us getting a win, is just a bonus," Arroyo said.
Jose Arredondo came on for the seventh and walked the first batter, Jason Castro. Fernando Martinez tripled up Tal's Hill in center field with one out to give the Astros a 2-0 lead. Ryan Hanigan picked off Martinez leading off third base for the second out. Greene hit a solo homer to deep left field to give Houston a 3-0 lead after seven.
After the Reds' five-run eighth, Jonathan Broxton struck out two in the bottom of the inning, and Aroldis Chapman recorded his 26th consecutive save, tied for the longest active streak in the Majors. He has 34 on the season.
Baker isn't worried about his players and coaches talking about the postseason too early; he's worried about his players listening to postseason talk from people outside the organization.
"This game is very cyclical," Baker said. "Things can happen rather quickly. You've just got to keep playing. You've got to keep grinding and grinding until you win it. A big lead means nothing until you win."
Nothing has changed for Heisey with the Reds closing in on a playoff berth.
"If we can keep widening the gap, that's what we want to do," Heisey said. "If you can win every game you can, you don't have to worry about watching the scoreboard."