Alex Nicholls was the Cobblers' hero when he floated in an 82nd minute equaliser after Aidy Boothroyd's side had trailed 2-0 and 3-2.
Burton dominated the first half but had only Calvin Zola's goal to show for their efforts. The striker struck in the ninth minute with a low shot after crashing a header against the underside of the crossbar.
Cobblers goalkeeper Lee Nicholls rescued his side by keeping out a Robbie Weir shot before tipping a Zander Diamond header onto the crossbar. The visitors could have snatched the equaliser against the run of play but Abebayo Akinfenwa's shot was pushed round a post by Stuart Tomlinson.
The hosts were rewarded with their second goal when Northampton's Langmead turned a Billy Kee cross into his own net in the 55th minute. However, Langmead quickly made amends by heading home Ishmel Demontagnac's free kick to reduce the deficit four minutes later.
Akinfenwa hit a post before David Artell struck in a goalmouth scramble to bring the scores level in the 74th minute. Skipper Diamond headed in a Damien McCrory free kick to put Burton back in front in the 79th minute, but it was Nicholls who had the final say.