The Brewers belied their League Two status and made light work of their East Midlands rivals, winning the game with a three-goal salvo in 15 second-half minutes.
The Foxes, who had made eight changes, controlled the opening exchanges but they could not create any clear openings and Burton took advantage thanks to a large chunk of fortune in the 20th minute.
Brewers striker Calvin Zola was hauled down on the edge of the area and from the resulting free-kick Chris Palmer's effort took a wicked deflection off the wall, wrong-footed Kasper Schmeichel and went into the net.
The hosts had plenty of opportunities to level before the break, but the heroics of Burton goalkeeper Ross Atkins ensured his side's lead remained intact.
After Ritchie De Laet criminally headed Anthony Knockaert's cross wide from close range, Atkins denied Jeffery Schlupp with a superb stop, kept out Paul Gallagher's effort and then turned over Martyn Waghorn's drive.
Nigel Pearson's men continued their assault on Atkins' goal after the restart but they were hit by a sucker-punch as the Brewers gave themselves some breathing space in the 53rd minute.
Foxes defender Zak Whitbread allowed the ball to bounce from a long clearance and Cleveland Taylor stole in and finished powerfully from the edge of the area.
Leicester got back into the game, though, as Knockaert fired in a 20-yard free-kick on the hour, but it proved to be in vain as Robbie Weir's penalty four minutes later restored the Brewers' two-goal cushion.
And that was a three-goal lead soon after when Jacques Maghoma thundered in a swerving 30-yard effort as Burton ran riot.
The Foxes tried to make a game of it, but Marko Futacs' late hooked finish, which made it 4-2, was too little, too late.
