Stephen McLaughlin headed the Shrimpers in front at the Pirelli Stadium before the Brewers' John-Joe O'Tolle was dismissed for violent conduct.
But Burton were still able to secure a share of the spoils with Scott Fraser curling home a fine free-kick at the start of the second half.
With 15 minutes on the clock, the Shrimpers came close to opening the scoring when Brandon Goodship's fine cross from the right hand side picked out McLaughlin whose downward header was tipped onto the crossbar by Burton goalkeeper Kieran O'Hara.
But McLaughlin was not to be denied for long and, five minutes later, he broke the deadlock when he rose high to head Isaac Hutchinson's driven right wing corner into the back of the net from eight yards.
Twelve minutes later, the Brewers suffered a further blow when O'Toole was shown a straight red card for violent conduct.
The ex Shrimpers loanee clashed with Tom Hopper when the Blues striker was grounded on the floor and was immediately dismissed by referee Darren Drysdale.
The visitors attempted to make the most of their extra man with McLaughlin having a well struck long-range free-kick gathered by O'Hara at the second attempt.
But, despite the numerical disadvantage, Burton bit back to equalise just four minutes into the second half wen Fraser curled an impressive left footed free-kick into the top right hand corner of the net.
Blues boss Sol Campbell responded by making his first change of the night as the fit again Stephen Humphrys replaced McLaughlin.
However, just before the hour mark, Burton came close to taking the lead when David Templeton smacked a 20 yard shot against the crossbar.
The Shrimpers soon made a second alteration with Simon Cox taking the place of Sam Mantom in the 65th minute and, 10 minutes later, Eren Kinali replaced Goodship for his first team debut.
But Blues - who had Nathan Ralph carried off late on - found it tough to create clear cut chances as the clash ended all square