Maholm's effort, combined with a big fifth inning, helped the Pirates even up the three-game series at one game piece.
"It was an overall good win for us," manager John Russell said. "We played good defense. It was a solid game, all around."
Maholm was able to get ahead of hitters all night. His 22 first-pitch strikes helped set up five strikeouts, and he walked none.
His only two blemishes came on two pitches. In the third, he left a hanging curveball over the plate for center fielder Corey Patterson. Later, he left a meaty fastball for right fielder Jay Bruce. Both pitches landed in the right-center-field seats for solo home runs.
Every other time Maholm found trouble, his defense would bail him out. Michaels had two diving catches in right field, including one along the foul line to end the game, and Andy LaRoche dove and threw out pinch-hitter Adam Rosales from his knees in the sixth. The Pirates also collected three double plays for Maholm.
"They're really alert because he's throwing sinkers and changeups and stuff," Reds skipper Dusty Baker said. "He's been pitching great, according to our reports, as of late. He had a lot of defensive help tonight, especially with double plays."
Maholm outdueled Reds starter Josh Fogg, who was hit hard for four runs and six hits in 4 2/3 innings. Ironically, Fogg, a former Pirate, came into the game as the career leader in wins (20) at PNC Park.
With his victory Wednesday, Maholm (8-7) is now two games behind Fogg and sits in second place with current Pirates starters Zach Duke and Ian Snell.
"It was just going after them, staying ahead," Maholm said. "The home runs happen. I just kept going after the guys.
"I was just trying to get deep into the game and take the load off the bullpen. Everything was, once again, just mixing pitches. I had a lot of sinkers for ground balls. I threw the breaking pitches when I needed them."
The Pirates' four-run outburst in the fifth was welcomed with open arms by Maholm. In the southpaw's previous three starts, the Pirates scored only two runs while Maholm was on the mound.
Brandon Moss helped prevent that from happening again with his double to right field, followed by Michaels' line-drive home run to the bleacher seats in left field to take a 2-1 lead.
Maholm then struck out trying to bunt and Freddy Sanchez flied out to almost extinguish the rally, but the Pirates managed to load the bases for Ryan Doumit, who came within inches of a grand slam when his hit banged off the Clemente Wall in right field. The Pirates' catcher settled for a two-run double.
"They picked me up," Maholm said. "I missed the bunt [and] we ended up scoring four. That was big. For me, it was going out there and putting up a zero."
Moss capped off the win with his first career home run at PNC Park in the eighth and John Grabow came in and picked up his third save of the season with a 1-2-3 ninth.
Maholm's numbers don't end there, however. He's given up two or fewer runs in seven of his last nine starts. He's also pitched eight innings in seven starts this year and has gone at least six innings in his past 18 starts since May 3.
"He goes right after the hitters," Michaels said. "He's not pitching around or trying to get guys to swing. It looks like he's just going right at them and the end result he's becoming the winning pitcher a lot more."
"He's a guy that when you send out there you feel like you have a really good chance to win," Russell said.