The Blades broke the deadlock early in the second half as replacement Callum McFadzean's deflected drive from distance crept into the bottom corner.
Look back at a big win for Chris Morgan's side with Sports Mole's minute-by-minute commentary below.
He told reporters: "We've been here before but everything is new. History is there and you can't change it. We've known for a few weeks that it will be the play-offs and that has been the players' mindset.
"We've got a talented group of players and we know what makes this team tick. We've got players who can score goals in big games.
"Their front two are excellent and they work well together. The team has a great team ethic and they work hard. We know what they do well and we have to prepare for two tough games."
He told reporters: "I think we have to aim to win tonight. We must make sure we keep possession at places like this. I'm pleased we have key players fit and if we play our game tonight we'll get chances to score, no question."