Nigel Clough thought the Blades were good value for the 1-0 win over Doncaster Rovers at the Keepmoat Stadium on Saturday.
Despite playing just under half an hour with ten men, following Paddy McCarthy's red card for a foul on James Coppinger, which led to Mark Howard saving Harry Forrester's penalty superbly, Jamie Murphy struck a decisive blow in the 64th minute to earn the Blades a deserved win against the odds.
An delighted Clough remarked: "We were fantastic in the second-half after a first-half that had very little between the teams, although we thought we should have had another penalty when we were given the free-kick on the edge of the box.
"It was a proper derby, a keenly contested fixture, there were a few strange decisions, but once we got in front we defended our lead excellently.
"Believe it or not we have confidence in Mark (Howard) when it comes to saving penalties, he is one of the best goalkeepers in the league and even in that situation we fancy his chances of keeping the ball out of the net.
"After Mark's save, given the red card to Paddy, we are thinking about holding out for a point, but with players like Jamie Murphy in your team you always have that ability to nick a goal."
The Gaffer added: "With ten men we had no option but to go 4-4-1, but what we always wanted to do is keep our goalscorers out there for as long as possible.
"The first-half was very stopstart with lots of free-kicks and bookings, but before the penalty we were dominating at the start of the second-half and a goal for Doncaster would have certainly been against the run of play.
"It was a special goal to break the duck of not scoring in the last three matches and from the touchline we had a fantastic view of the ball dipping into the net."