HOUSTON -- Bronson Arroyo got all the backing he needed from a trio of longballs.
The Reds opened a seven-game edge over second-place St. Louis. Cincinnati stopped a six-game road losing streak.
Arroyo (16-10) pitched four-hit ball for six innings, striking out five and walking one.
"We had an excellent pitched game out of Arroyo," manager Dusty Baker said. "He continued his streak of 200 innings for the year and won his 16th game."
"He's Mr. Consistency," he said.
Arroyo reached the 200-inning mark for the sixth straight year.
Bruce's two-run homer highlighted a four-run fifth as the Reds took a 7-1 lead. Joey Votto started the inning with a double and Bruce connected one out later off Nelson Figueroa (5-3) for his 21st home run.
"It gave us some cushion and my family was here to see it," Bruce said.
"We haven't been hot lately so it was nice to get out there tonight and get some runs on the board," he said.
Reliever Henry Villar walked the first two batters he faced, Ryan Hanigan hit an RBI single and Arroyo had a sacrifice fly. Villar also hit Brandon Phillips with a pitch and had a balk before Gustavo Chacin came on to get the final out.
Edmonds made it 3-1 in the fourth with a leadoff homer, his 10th of the season. Stubbs homered on the first pitch from Felipe Paulino in the seventh.
Cincinnati got three more runs in the ninth on a double by Hanigan and two-run single by pinch-hitter Yonder Alonso.
Arroyo said he tired in the sixth inning but got lucky.
"A couple of balls were hit right at Jay (Bruce) and we put enough runs on the board to let me pitch at ease," Arroyo said. "I gave up the homer early to Carlos and that happens a lot with him in this ballpark."
Figueroa's loss snapped a string of 17 straight games without a loss by Astros starting pitchers. Astros starters were 9-0 during the streak.
"Well, it's been a while since we had one like that," Astros manager Brad Mills said. "That's for sure. I know Figgy only had two walks, but it seems like he was in deep counts the whole game."
Carlos Lee led off the Houston second with his 23rd home run for a 1-0 lead.
"These games are going to happen," Lee said. "Hopefully, it doesn't happen often. It was one of those games that got out of hand."
"Arroyo pitched pretty good. He usually does against us. You have to give credit to them. They came out today, got some big hits and some long balls."
Cincinnati scored twice in the third, helped by third baseman Chris Johnson's throwing error. Orlando Cabrera and Scott Rolen hit RBI singles.
The Reds have struggled on the road lately.
"We struggled last road trip and now we're 1-1 on this road trip," Baker said. "We've got to forget about that last one and go forward on this one."
Reds OF Laynce Nix was activated from the disabled list after recovering from a sprained left ankle. ... Arroyo is one of four major league pitchers to win at least 15 games in each of the last three years.