The Brewers had the best of the limited scoring opportunities in a hard-fought first half.
They were unable to capitalise on an indirect free-kick inside the visitors’ area in the 32nd minute. And Rotherham had another scare seven minutes later as Steve Kabba’s shot came back off the legs of Andy Warrington and young defender Tom Parkes headed the rebound wide from eight yards.
Le Fondre gave the Millers the lead in the 52nd minute by scrambling the ball over the line to punish poor defending by the home team after Warrington’s long free-kick had bounced into the penalty area.
The visitors had chances to double their lead, but a Le Fondre header came back off the post and Burton keeper Artur Krysiak had to use his legs to deny Nick Fenton.
The Polish stopper produced more heroics to deny Le Fondre in the 74th minute as the Millers took control of the game.