It was a relatively quiet first half, with the teams returning to the dressing rooms goalless. Burton's Jonny Smith picked up a yellow card in the sixth minute and although Posh took more shots, the Brewers had more on target.
Two goals in quick succession were enough to keep Burton in possession of the full three points. Kane Hemmings struck nine minutes after the restart and Hayden Carter's shot crossed the line four minutes later, after some good work from Tom Hamer to keep a corner alive.
Peterborough continued pressing - with 19 shots compared to Burton's eight - but couldn't find the back of the net until five minutes into injury time, when Harrison Burrows nabbed a consolation goal for his side.
A philosophical Darren Ferguson was left to rue a below-par performance at both ends of the pitch on a rare off-day for his side. He said: "It is a disappointing day, we haven’t had too many of them lately.
"Quite simply, it is not hard to analyse why we lost the game; we were not good enough in both boxes. Funnily enough that is the last thing I said to the players before the game and it’s what has cost us."
Ferguson was disappointed to concede the first from Hemmings, but even more so with the second that gave Albion a vice-like grip on the game.
He continued: "We gave away two cheap goals, the first one in particular. It was poor to concede a second goal so quickly after that, we still had a long way to go in the game at that point.
"We created opportunities, but the composure and quality wasn’t there. You are losing games if you’re not good enough in both boxes.
"Even with 10 minutes to go, I felt if we got one goal we could get back into it.
"I said to the players afterwards, we need to react, we need to move on quickly. We can’t get it back. We have to look ahead and it is the perfect game for us on Tuesday to do that. I think it is a great game for us on Tuesday."
The result sees Posh slip back to second in the Sky Bet League One table, level on 62 points with Hull City - the team they face at the Weston Homes Stadium on Tuesday evening - but with two games in hand.
Lincoln City returned to winning ways against Crewe Alexandra today, rising to 60 points.