Coming off a three-game sweep of the World Series champion Boston Red Sox at Fenway Park, the Brewers won their fourth straight game and improved to 5-2.
Kyle Lohse (1-1) allowed three runs and seven hits in five innings, walking five.
Braun connected twice off Kyle Kendrick (0-1), snapping the longest homerless drought of his career. The 2011 NL MVP came in with only three singles in 20 at-bats this season.
But Braun, who is bothered by a right thumb injury, felt just fine - as usual - in Philadelphia. He has 10 homers and 21 RBIs in 20 career games at Citizens Bank Park.
Braun was booed in his first game in Philly since serving a 65-game suspension for violations of Major League Baseball's drug agreement and labor contract. He also got an earful last week in Boston.
It didn't bother him.
He hit a three-run shot to left in the third to put the Brewers up 4-1, ending his streak of 98 plate appearances without a homer. He hadn't hit one since May 22, 2013, against the Dodgers. Braun's solo homer in the fourth made it 6-1. He then launched a three-run drive off Brad Lincoln in the eighth.
Braun also turned in a defensive gem. He saved two runs with a diving catch on Carlos Ruiz's sinking liner to right to end the second inning.
The game was scheduled for Monday afternoon, but was postponed Sunday because of a rainy forecast. It was sunny and 62 degrees at first pitch, but windy enough to cancel the Navy parachuters who deliver ceremonial baseballs. Former Phillies pitcher Jamie Moyer, now a broadcaster, threw out the first pitch. It was brought to him by his boyhood idol, Hall of Famer pitcher Steve Carlton.
The Phillies could've used them on the mound against the Brewers.
Kendrick allowed six runs - four earned - and nine hits in five innings.
Jimmy Rollins had an RBI double in the fourth and an RBI single in the sixth to get the Phillies to 6-4.
Five-time All-Star second baseman Chase Utley wasn't at the ballpark because of the flu. He was replaced in Philadelphia's lineup by rookie Cesar Hernandez.
A sellout crowd of 45,061 enjoyed the pregame festivities that included the traditional mini-parade that leads players into the ballpark from the street behind the stands in left-center field. Players and coaches walked in, mingled with the crowd and high-fived fans lined up along the red carpet in the outfield.
NOTES: Braun's other three-homer game was against San Diego on April 30, 2012. ... Eight Brewers have had seven RBIs in a game. Jonathan Lucroy was the last to do it on Aug. 30, 2012. ... Phillies LHP Cole Hamels said he could be ready to join the rotation after two more rehab starts in the minors. Hamels, the 2008 World Series MVP, was slowed by shoulder discomfort in spring training. He's scheduled to pitch Friday night for Class-A Clearwater. ... Braun passed Geoff Jenkins for third place on the Brewers' career list with 214 homers. He has 17 home runs and 37 RBIs in 44 career games vs. the Phillies. ... Rollins already has eight RBIs, one more than he had last April. ... RHP Matt Garza (0-1, 1.13 ERA) takes the mound for the Brewers on Wednesday night. Roberto Hernandez (1-0, 3.38) goes for Philadelphia. Garza is 2-1 with a 1.30 ERA in five career starts against the Phillies. Hernandez will make his first start vs. Milwaukee.