Cody McDonald's first goal for Gillingham gave the Kent side only their second win over the season against Burton.
Both sides hit the bar in the first half with Shaun Harrad's free-kick rattling the frame of the goal for the Brewers before McDonald was unlucky to break the deadlock with a header.
But he did get the only goal of the game early in the second half when he nodded in Chris Palmer's free-kick.
Going in search of their first away win of the season, Burton almost got off to the best possible start when Harrad's first-minute free-kick hit the bar before he forced a great save out of Lance Cronin.
The Gills ended the half the strongest and after 44 minutes McDonald met Palmer's corner perfectly, but headed onto the crossbar.
Gillingham started the second period much more positively and got their reward after 50 minutes when on-loan McDonald headed in. The 24-year-old went close to doubling Gillingham's lead while Danny Spiller also forced a good save from Adam Legzdins.