Despite the late goal from Harrison Burrows, Burton held on.
Jimmy Floyd Haselbaink has got the Derbyshire side playing fantastic football, fighting hard and now will be as confident as ever that his team are going to avoid relegation, where two months ago they looked dead and buried.
Story of the game
Inside the first minute, already the hosts proved to be a threat, Danny Rowe eventually got onto the end of a long throw, but his shot was not enough to beat Peterborough 'keeper Christy Pym.
The away side had the best of the opening fifteen minutes with a couple of half chances here and there. They had five corners in the first quarter of an hour, that could be a record!
Darren Ferguson's side applied plenty of pressure to the Brewer's early on, with the home side's defence being tested on multiple occasions.
The Brewers came close on the 23rd minute, Rowe causing more problems for the home side and Pym was forced into a fine save after the 28-year-old cut in onto his left foot.
A clash of heads caused a lengthily stoppage after 25 minutes as Micheal Bostwick and Sammie Szmodics clashed heads in the box after a Burton corner ball.
After the half hour mark, Posh attacked the Yellow's with multiple efforts going way off target. Unable to cause Ben Garratt any major problems in the Burton net.
Five minutes were added at the end of the first half after the clash of heads.
There was a chance for Peterborough at the end of the half as a free-kick was taken by Dan Butler and cut back across goal, but no blue shirt could get on the end of it.
As the first half came to an end, either side couldn't find an opening goal. Posh dominated the ball in most areas, however a stubborn and well organised Burton defence didn't allow for anything to slip.
The Brewers certainly matched the league leaders, and it seems like a game where one goal could decide the outcome.
It was a slow start to the second half with both teams just playing with the ball and giving it away.
However, on the 55th minute who else but Kane Hemmings was there to smash Burton ahead against the odds. He got on the end of a rebound after a Jonny Smith shot was saved by Pym.
Just three minutes later, the home side doubled their advantage! January signing Hayden Carter poked the ball in. It wasn't clean but Jimmy Floyd Haselbaink will take it everyday of the week. The 21-year-old has been terrific since signing on loan from Blackburn rovers in the new year.
With now a two goal deficit, the pressure was on for Posh to pull a goal back, the next one to have a half chance was Jonson Clarke-Harris, who was then brought off a minute later. The League One top goalscorer was a doubt for the game, but was deemed fit to play, so the substitution was probably a precaution for the away side.
Ferguson made another change, this time bringing off Butler for Harrison Burrows in a fight to get back into the game.
They say that a 2-0 lead is the most dangerous score in football. Burton almost caved in and conceded but thanks to a Carter block off the line the score stayed the same. Mohamed Eisa's shot was stopped by the youngster after Sikiri Dembele slipped the 26-year-old through.
Since he replaced Clarke-Harris, Eisa was a huge threat for the visitors. He latched on to a long ball and his lob beat the goalkeeper but went just over the bar.
A late consolation in the last kick of the game pulled one back for the visitors, Burrows with the strike.
Despite late pressure from Peterborough, Burton had the willpower to hold on for an exceptional result, which will go down a treat and could prove costly to Posh, who lose the top spot after Hull won. What a chance missed for the away side, but what a chance taken from the hosts. It ended 2-1.