Gary Rowett hailed a "magnificent performance" from his Burton side as they shattered Southend's 14-game unbeaten run despite ending the game with 10 men.
Burton had defender Nathan Stanton sent off for a second yellow card 15 minutes from the end but rarely looked like surrendering a 2-0 lead given to them by top scorer Calvin Zola and midfielder Lee Bell.
Burton boss Rowett said: "Our effort and work-rate was first class and I thought we created some good opportunities against a team that hasn't conceded an awful lot of goals in the course of a fantastic run of results.
"We've proved again that when we're on our mettle and do the right things, we're capable of causing anyone problems. Even at 10 men we limited them to very, very few chances which shows what a great group of players we've got."
But Rowett was less than complimentary about Stanton after the defender was given his marching orders for his part in an off-the-ball spat with Southend defender Luke Prosser.
The Burton boss said: "It was stupid of someone with his experience to get involved. The first booking I found difficult to understand, but he still shouldn't have got involved in something that gave the referee the chance to send him off."
Burton took the lead in the 16th minute when Zola slid home a Bell cross from six yards for his 11th goal of the season and they doubled their advantage in the 36th minute as Zola played the ball across the edge of the area and Bell's fierce shot took a big deflection off Southend skipper Chris Barker to leave 'keeper Paul Smith stranded.
Shrimpers captain Barker said: "It was just one of those days as far as we were concerned. We tried and tried but it just didn't work for us. We just didn't play very well. They had a lucky break with their second goal because I think the shot would have been closer to the corner flag until it hit me and went in.
"That's what happens sometimes when things don't work out for you. I think you've also got to give Burton credit as well because they battled, tackled and bullied us a little bit, which hasn't been the case in the run we've had.
"But if we lose only once every 15 games, I'll take that until the end of the season. We've got another game on Tuesday, so we've got to reorganise and make sure we bounce back with a win."