Howard won it with his 28th homer of the season, driving a 2-1 pitch off struggling Rafael Soriano (1-4) into the center-field seats to break a 2-all tie. Philadelphia extended its lead over Atlanta in the NL East to six games.
Joe Blanton surrendered only one earned run in seven innings, Ryan Madson (4-4) won it with a scoreless eighth and Brad Lidge escaped trouble in the ninth for his 22nd save in 29 chances.
After struggling in his two previous starts, Braves starter Jair Jurrjens allowed just two runs on five hits in seven innings. But Soriano, pitching for the first time in nearly a week, couldn't get past Howard. The Atlanta closer has given up five runs in his last four appearances, getting through only one of them unscathed.
The Braves threatened against Lidge, who came into the game with a 7.29 ERA. Adam LaRoche singled to center with one out, and pinch-runner Matt Diaz stole second. After pinch-hitter Greg Norton walked, Nate McLouth ended it with a drive to the warning track that was caught by Raul Ibanez in the left-field corner.
Atlanta jumped ahead in the first. McLouth, who had missed the last three games with a sore left hamstring, led off with a double into the right-field corner and came around to score on Chipper Jones' one-out single up the middle.
Utley put Philadelphia ahead in the fourth. Victorino led off with a single and Utley followed with a drive into the right-field seats that was never in doubt, nearly reaching the second section. Victorino put on a real show in center field.
He ended the fifth chasing down a drive by Brian McCann, leaping up to catch it before he slammed into the padded well. Blanton slapped his glove and pumped his first on his way off the mound, while McCann buckled over in disbelief after rounding first. The catch prevented McLouth from scoring the go-ahead run.
Victorino wasn't done, either. Garret Anderson led off the sixth with another towering shot, this one to right center. The Phillies outfielder caught it reaching back over his right shoulder with his left arm, lost his balance and tumbled into the wall.
The Atlanta defense came up big, as well. Chipper Jones made a brilliant diving catch to end the second when Pedro Feliz ripped a liner than looked to be headed into the left-field corner. Jayson Werth was running from first on the play and might have gotten around to score if Jones hadn't made the grab.
NOTES: An error by Phillies 3B Feliz led to an Atlanta run in the fourth. Yunel Escobar reached and Church brought him all the way home with a two-out double. ... The Braves fell to 17-10 since the All-Star break.