A record 11,033 fans turned at the brand spanking new New York Stadium, but due to crowed congestion entering the League Two stadium the kick-off was delayed by a good 20 minutes. United turned out a strong side with new signings Tony McMahon and Shaun Miller being given a run out in the second half, but it was this summers first signing, John Cofie who made the difference in an action packed first half.
The winner was scored five minutes before the break - a curling effort from Cofie, he displayed a 'cool head' to lift the ball over Scott Shearer in the Millers goal to hand the Blades the lead and the match winner.
United - wearing the brand new all black away kit with orange sash, started the brightest of the two sides and within a minute have carved out an opportunity but Harry Maguire turned his header wide. The hosts hit back via former Barnsley striker Daniel Nardiello who had helped himself to a goal in last season 'entertaining' 4-4 home draw with Exeter City, he ran clear of the defence but Mark Howard was quick to clear - the home side the ball in the old onion bag when Pringle's free-kick deflected into the net, but the goal was ruled offside.
In further advances for either side the woodwork took a battering, for United, a Ryan Flynn corner was headed against the post by a much involved Maguire whilst at the other end Pringle again was unlucky with his free-kick, his 20 yard effort smashing the crossbar - this before 20 minutes of play had passed by.
Howard was then forced into a save from both Pringle and Ainsworth before, with a hint of magic, took the lead through Cofie. Erik Tonne found the on-loan Red Devils striker wanting, who bided his time before curling over Shearer from the left hand side; 0-1. Before the half-time whistle blew the visitors almost doubled there lead when David McAllister saw his close range header saved.
Blades boss Danny Wilson made some changes in the second half and before the final whistle introduced six changes, but it was the home side who had the opportunity of the first chance. In a ex-Tykes one-two, Nardiello robbed the ball from Maguire who fed Keyode Odejayi who the big striker couldn't capitalise on the young defenders error.
Substitute striker Miller, playing in Blades colours for the first time since his move from Crewe Alexandra controlled the ball neatly with his first touch which almost created a goal, meanwhile captain Michael Doyle fired wide for the Blades.
With ten minutes remaining Taylor fired over the top for the hosts as they looked to level the scores and Stephen Quinn blocked Pringle's effort - the final chance of the match fell to the 'Ginger Messi,' Quinn but Shearer tipped the ball around the post before match referee Howard Webb sounded full-time.
Rotherham United: Shearer, Bradley, Mullins, Sharps, Wilson, Ainsworth (O'Connor 80), Arnason (Evans 80), Noble (Taylor 63), Pringle, Odejayi, Nardiello (Agard 63).
Unused: Warrington, Revell, Rose.
Sheffield United: Howard, Westlake, Williams (McMahon 45), Montgomery (Doyle 45), Maguire, Hill, Flynn (McFadzean 73), McAllister (McDonald 45), Porter (Cresswell 70), Cofie (Miller 74), Tonne (Quinn 45).
Unused: Long, Ironside, Philliskirk.
Attendance: 11,033
Millers manager Steve Evans was impressed by his side, but felt that they should have left the game with something better than a defeat. He told themillers.co.uk; "We played some super stuff, we should have been in front after a couple of minutes when Nards goes through and tries a dink when he should pass it into the net. After that they scored a good goal to be fair, which was an individual error from our point of view, but the lad has executed the shot extremely well.
"Both sides passed the ball well, it was end-to-end for a time but I think on chances they've had two and we've had five and we have lost the game. I have said to the players that there is a lot of good stuff coming from us but there are still things we need to work on," added Evans.
Meanwhile, winning scorer John Cofie was happy to net at the New York Stadium in front of 3,500 traveling fans; "I got on to the ball, ran at the defender, looked up and managed to float the ball over the goalkeeper," Cofie told sufc.co.uk, of his first half goal. He added: "Of course, the aim is to deliver more goals - I'm getting fitter and sharper as the days progress and hopefully everyone will be just right when the season kicks-off.
"I enjoyed the game at Rotherham. We spoke about the game plan and I think the Gaffer's style of play fits me well because I like running behind defenders. I want to do well and work hard for the team, that is all that matters."