Josh Harrop was given a place in the starting eleven and he paid his manager back in kind as his second half effort from outside the box was parried by the United keeper into the path of Browne who tapped home for the only goal of the game.
There were nervous moments for the visitors with Cunningham blocking an attempt on goal and Rudd having to make a couple of saves but Preston held on for the victory.
It was North End's first double over Sheffield United since 1895-6. It also ended the home sides chances of catching the top six. Bristol City and Millwall also ruled themselves out of a top six finish with their respective results.
Derby drew away at Aston Villa with the home side scoring a late equaliser. It means that Derby sit in he final play off spot only two points ahead of North End but with a far superior goal difference.
Derby play at home to Barnsley who are trying to avoid relegation and if Derby pick up anything from the game then they will be confirmed in the end of eason lottery. If Derby lose then Preston must defeat Burton on Sunday in order to take sixth spot.