Maholm (2-2), who tossed his third career complete game, gave up one run on two hits, walked four and struck out two as the Bucs snapped a three-game losing streak.
"That's something we've been looking for -- for awhile," Pirates manager John Russell said. "You don't always expect somebody to go nine innings, but it's a huge lift for us. Not only for our offense and our defense and our bullpen, but I think it's a huge lift for the rest of the starters. Now they have something to grasp hold of and say, 'Hey, we can do this.' Obviously, it was a great job by Paul, and I think it shows the rest of our starters we're still OK."
Maholm was pleased with his effort.
"I was changing speeds and trying to attack with my sinker," he said. "[On] those four walks, I was trying to attack the hitters. I wasn't trying to throw around them, my release point was barely off, but I was confident enough to get the ground ball or to get the easy popup."
Phillies manager Charlie Manuel gave a tip of the cap to Maholm.
"He threw strikes and he had a low pitch count, and we swung the bat," Manuel said. "I felt like we hit a few balls real good and they caught them all. But at the same time, I have to give him a lot of credit because he pitched a good game. He threw strikes and he was making us swing the bat."
Phillies starter Brett Myers (2-2) absorbed the loss, allowing four runs on eight hits in five innings.
The script was different than the first two games of the series, as the Pirates were the team that made noise in the first inning. First, Maholm set the Phillies down in order in the top of the first inning. It was only the fourth time this season that the Pirates have accomplished that feat.
"The defense was great and [Jose] Bautista did a good job, [Xavier] Nady with a diving catch and we turned some double plays," Russell said. "It was a solid game all the way around, and that's what starting pitching will do for you, with the way we've been playing. The guys know we can score and they get into it. You get a start like that and guys really respond, and that's what we've talked about, and starting pitching really sets the tone."
In the bottom of the first, Nate McLouth led off with his fifth home run of the season.
Pittsburgh made it 2-0 in the fourth. With two out, Adam LaRoche singled, advanced to second on a wild pitch and scored on a RBI single by Bautista. The Phils avoided further damage when center fielder Jayson Werth threw Bautista out at home following a Luis Rivas single.
The Phillies broke through against Maholm in the top of the fifth. Pat Burrell doubled and scored on a Eric Bruntlett single, slicing the Pirates' lead to 2-1.
McLouth tagged Myers again for his second home run, a two-run shot in the bottom of the fifth, increasing the Pirates' lead to 4-2. It was the second two-homer game of his career. He hit two against Colorado on Aug. 22, 2007.
"McLouth is a pretty complete player," Russell said. "Guys feed off Nate and he's one of the catalysts of our club. When he goes pretty well, things seem to go pretty good. Now that everybody else is starting to swing the bats a little bit better, it takes some of the heat off him and guys are starting to relax."
"Whenever you're hitting the ball hard, you're seeing it well," McLouth said. "Things are slowing down for you, and I happened to get a couple good pitches to hit today and didn't miss them."
Pittsburgh tacked on an insurance run in the sixth to make it 5-1.
After finishing the homestand 3-4, the Bucs head to New York for a three-game series with the Mets starting Monday.
Said McLouth: "I think once everybody starts clicking the way we can ... once we all start doing that in the lineup, we're going to score some runs."
George Von Benko is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.