After Jerry Hairston Jr. drew a leadoff walk in the bottom of the seventh in a 4-4 game, Votto put Tim Byrdak's 1-0 pitch into the left-field seats for his eighth homer of the season.

Bothered by an inner ear infection and dizziness for two weeks, Votto did not start the past two games. In his previous start on Saturday vs. the Indians, he slugged two homers in his first game back after missing a week.

In his first relief appearance back from the disabled list, Nick Masset (2-0) pitched the seventh inning and earned the victory for Cincinnati.

Reds starter Micah Owings was finished after five innings and allowed three earned runs and six hits with four walks and three strikeouts for a no-decision.

After Laynce Nix's solo shot in the fourth inning tied the game at 3, Houston rallied. In the sixth, Jeff Keppinger hit reliever Mike Lincoln's first pitch for a homer to left field and a 4-3 Astros lead.

Astros starter Roy Oswalt put himself into a big jam in the Reds sixth with a runner on first and one out. He walked Alex Gonzalez and hit Adam Rosales with a pitch that loaded the bases. A four-pitch Oswalt walk to pinch-hitter Jonny Gomes scored the tying run. Oswalt, who is 23-1 lifetime vs. Cincinnati, got a no-decision after pitching six innings and allowed four runs and seven hits.

There was a 39-minute rain delay at the start of the game. The Reds, winners of four of their past five games, have taken the first two games of the three-game series vs. Houston.