Howard rallied the Phillies back into first place, hitting a go-ahead homer in the eighth inning for his fourth hit in an 8-7 victory over the Atlanta Braves on Tuesday night.
"He's big in the moment," manager Charlie Manuel said after the Phillies' fifth straight win.
Brad Lidge escaped a bases-loaded jam in the ninth and Philadelphia moved a half-game in front of the fading New York Mets, who lost 1-0 at Washington. The Phillies also caught the Mets in September to win the division last season.
Howard's homer was his 45th of the year and 38th in September over the last four seasons, the most in the major leagues. Howard said he had no idea why he thrives in the month.
"Maybe it's just the pennant races are heating up," Howard said. "I'm just trying to go out there and do what I can to help my team."
After trailing the Mets by 3½ games going into last Thursday, Philadelphia leads the division for the first time since Aug. 26.
Manuel said he saw the Mets' final score as his team was trying to rally.
"I think we won a big game," Manuel said. "We've got 11 more to play."
Howard insisted he waited until after the game to look at other scores.
"To win the way we won was definitely big," he said. "Now you can step back and look at the division and look at all the rest of the races and see where we are."
The Phillies led 3-0 and 4-3 before the Braves took a 7-4 advantage with a four-run sixth.
Howard had a run-scoring triple as the Phillies scored twice in the seventh.
Lidge walked Chipper Jones to open the ninth, then walked Casey Kotchman and Jeff Francoeur to load the bases with two outs. But the All-Star closer struck out Gregor Blanco, making him perfect in 37 save chances during his first season with Philadelphia.
The Phillies improved to 71-0 when leading after eight innings. They are 7-0 at Turner Field this year and 11-2 overall against the Braves.
Howard has thrived against the Braves. He is hitting .375 (21-for-56) with six homers and 21 RBIs against Atlanta.
Julian Tavarez walked Jayson Werth with two outs in the eighth. Braves manager Bobby Cox brought in Mike Gonzalez (0-3), who gave up Howard's opposite-field homer to left. It was Gonzalez's second blown save in 13 chances.
"I'm usually good with him as a hitter but when you put one there right in his wheel house, man," Gonzalez said. "I mean, I went back and looked at the pitch. If I get it where I need it ... it was right where he hits it. I was trying to get it up. His pitch is down and away. It was just a bad pitch."
Braves catcher Brian McCann defended Gonzalez, saying Howard hit a good fastball.
"When he's locked in, he's as good as it gets," McCann said.
Manuel struggled to describe the homer.
"It's a big hit. A great hit. A tremendous hit," he said.
Making a late push for NL MVP despite a .249 batting average, Howard leads the majors in homers and RBIs (136). He was 4-for-5 with three RBIs.
Ryan Madson (4-2) had three strikeouts in two perfect innings.
Jamie Moyer gave up six hits and six runs in 5 2/3 innings. He walked four batters, including back-to-back walks to Brent Lillibridge and Greg Norton to load the bases in the Braves' big sixth inning.
Josh Anderson tied the game with a groundout. Kelly Johnson's pinch-hit single off Chad Durbin drove in two runs to extend his career-best hitting streak to 14 games. Brian McCann added a run-scoring single off Scott Eyre for a 7-4 lead.
Werth, who hit a two-run homer, and Shane Victorino each had three hits.
Jimmy Rollins' third-inning double set up a three-run third inning. Chase Utley followed with another double to left-center, driving in Rollins. Werth's two-run homer to left gave the Phillies a 3-0 lead.
The Braves tied it in the third. With one out, Moyer hit Anderson with a pitch and walked Martin Prado. Jones' single loaded the bases. McCann drove in Anderson with a single. With two outs, Kotchman hit a two-run single. Jones scored the tying run on a slide that beat Victorino's throw from center.
Ruiz gave the Phillies a 4-3 lead with his homer in the fourth.
Manuel said rookie LHP J.A. Happ will replace RHP Kyle Kendrick as Wednesday night's starter against the Braves. Happ, who will be making his third start, has never faced the Braves. ... Braves SS Yunel Escobar missed his third straight start with a strained right hamstring. "We keep saying it's day-to-day, but I think it's a little worse than that," Cox said.