Harang remained in the game after getting hit in the left foot by a low liner off the bat of Craig Counsell with one out in the fourth inning.
"My foot hurts," he said after the game. "I just came in and made sure my shoe was tied to prevent any swelling. I wasn't as sharp as I wanted to be out there, but this was my first start in 11 days. It's hard to stay sharp, but I'm not worried. I limited them. I gave up a lot of hits, but they were all singles. I'd rather give up 10 singles than five extra-base hits.
"I'll get another crack at it next week in Colorado. I'll just have to work on staying sharp this week."
First baseman Joey Votto hit a pair of run-scoring doubles, left fielder Jonny Gomes added a two-run homer and third baseman Scott Rolen contributed a two-run double as the Reds improved to 4-1 on the six-game homestand that is scheduled to end Wednesday with the finale against Milwaukee. The Reds expanded their National League Central Division lead over St. Louis to seven games as the Cardinals lost, 3-0, at Houston.
"The Reds are playing great ball," Milwaukee manager Ken Macha said. "Since the All-Star break, they've absolutely been on fire. They're playing good team ball -- unselfish with their at-bats -- and their defense has been tremendous."
Cincinnati used two tremendous defensive plays to close out the game. With Ryan Braun on first and one out, Votto dove to his left into foul territory to grab Prince Fielder's bouncer, scrambled to his feet and threw Braun out at second. Casey McGehee followed with a grounder that Rolen grabbed and got Fielder at second with a lunging backhand flip to second baseman Chris Valaika.
The Reds survived a ghastly two-run error committed by Gomes, who let Chris Dickerson's routine single to left field off of right-hander Sam LeCure skip past him to the wall, allowing Braun and Fielder to score and cut Cincinnati's lead to 4-3 in the fifth inning.
Votto, whose two-run double in the first wiped out Milwaukee's 1-0 lead, responded by driving in Drew Stubbs from second in the fifth with a checked-swing, bloop double down the left-field line.
"Everyone's taking turns," Gomes said. "You saw it tonight. Even when we're up four in the ninth, guys are diving and making plays. We're situationally hitting, trying to execute squeeze bunts. Why change?"
LeCure (2-4) recovered to pitch two shutout innings and get the win with relief help from left-handers Bill Bray and Chapman -- who pitched an electrifying and perfect eighth inning in his Major League debut -- and right-hander Logan Ondrusek.
"We're starting to feel the buzz," LeCure said. "It's exciting."