Guy Whittingham breathed a sigh of relief as Pompey finally held on for an away victory.
Ricky Holmes and Simon Ferry put the Blues 2-0 up against Burton, only for Yassin Moutaouakil’s 84th-minute sending off to rock them.
Zander Diamond pulled one back deep into stoppage time – but the visitors held on to win 2-1.
And Whittingham was delighted to get the victory after three successive 2-2 away draws.
He said: ‘It was probably the game, out of all of them, we have created the least amount of chances for us and that is the balance we are looking for.
‘The first goal was great athleticism from Ricky and Simon does not get many tap-ins and it has trickled in.
‘Then we go down to 10-men.
‘The referee is left with no choice and Yassin going off made it a lot harder.
‘But we managed to hold on and get the victory and the players need a big pat on the back.’