Braun, who entered as a pinch hitter in the seventh, drove a pitch from George Kontos (2-3) to the center-field wall to score Domingo Santana and Eric Sogard. Braun got a chance to bat after Kontos walked Sogard, batting .105, on four pitches.
Josh Hader (1-0) pitched the final two innings to pick up the win. He surrendered Starling Marte's tying two-run homer in the top of the eighth, and then retired the Pirates in order in the ninth.
Braun was out of the starting lineup for the second consecutive game to rest a sore right calf. He struck out in the seventh, but came through in the clutch again with the game on the line. This season, the 2011 NL MVP is 7 for 10 with three homers and 13 RBIs with two outs and runners in scoring position.
The Brewers opened a 3-1 lead by scoring twice against Kyle Crick in the seventh. The right-hander struggled with control, walking three and throwing two wild pitches. Christian Yelich hit a tiebreaking RBI single, and Lorenzo Cain scored on a passed ball charged to catcher Francisco Cervelli.
Pittsburgh starter Jameson Taillon pitched five innings, allowing one run and six hits.
Milwaukee starter Jhoulys Chacin worked six innings. He was charged with one run and three hits.