Goal in each half denies hard working U's.
The U’s made just one change to their starting eleven. With Brian Wilson unable to overcome an ankle injury in time for this match, Bradley Garmston came in for his Football League debut with John White moving over to right back.
Other results around them went their way on Saturday so it remains very much as you were as the final games of February approach.
Boss Joe Dunne wanted his side to maintain performance levels if they couldn't get a result, and there was enough in the game to give them hope going into the coming home games in the next seven days.
And the icing was put on the cake for the home team, as Dave Kitson tapped home late in the game to seal a 3-0 win.
The U's fell behind early to a penalty, but kept themselves in a hunt for a point throughout the match and had chances to level things up before a second for the Blades with eighteen to go.
Sheffield United proved too strong in the end for a hard working U's side as they grabbed a goal in each half to send Joe Dunne's men to defeat.
That meant that only two players who started against the Blades in August – Magnus Okuonghae, celebrating his birthday at Bramall Lane, and Freddie Sears – were in the side for the U’s latest match.
After a bright start by the visitors, they found themselves one down after just five minutes. Barry Robson spun Josh Thompson in the box and went to ground and, despite protests from the U’s defender, the referee pointed straight to the spot.
Robson picked himself up off the deck and buried the penalty to give the Blades the early advantage in a big game for both teams.
Murphy was a lively character for the home team and he was having an interesting battle with White down the U’s right in the early stages.
The U’s were growing into the game though and Sears had a free kick deflected just over the bar before getting on the end of a Massey cut back to fire over the top from the edge of the box.
From another set piece won by Massey on the left, the ball eventually fell to Wright but the former Ipswich man lifted his effort well over the bar once again.
The U’s were looking lively, but they had to stay on their toes, as Doyle fired a warning shot against them with a volley from the edge of the box that Walker saved comfortably.
Sears was the U’s main man and he embarked on what is becoming a trademark run through the middle, with his shot clipping the centre half and forcing the keeper into a save.
The U’s had responded well to going behind, but they could have been two down a minute before the break.
Kitson rose to head past Walker, but the ball was still settling in the net when the celebrations were cut short by the linesman’s flag.
And the Blades still had time for another chance. Doyle picked up the ball and let fly with a superb shot, which crashed a shot against the upright with Walker beaten.
It meant that the U’s went into the interval with some hope of getting back into it, and they started the second half in decent enough fashion.
They looked like they were going to get in four on two on the counter, but Massey’s squared ball just caught Ibehre’s heel as Sears zipped in behind.
Ibehre then had a shot blocked as the ball dropped to him from a U’s throw, before Porter got away through the middle only to lift his shot over the bar.
The U’s were still pressing for the equaliser and they made their first change 20 minutes into the second half as Porter was replaced by Compton. The winger had had plenty of attention from the Blades defence and limped off after a challenge that had earned McMahon a booking.
The ex-Pompey man sent over a dangerous cross that Ibehre nearly turned home, before a Higginbotham tackle on Sears only just went wide of his own post.
The U’s made their second change with eighteen to go, Massey being replaced by Drey Wright.
But the winger hadn’t touched the ball before the Blades doubled their advantage as McDonald drove out of midfield and put one in the bottom corner beyond the reach of Walker.
It summed up a clinical display from the home team, who keep up the pressure on the promotion spots.
Walker pulled off a good stop to stop an initial effort but it fell kindly to Kitson, who really couldn't miss from a yard out.
Compton went into the book deep in injury time, but the final word was to go to the Blades.
As the U's sought any kind of route back into the game, they were finding the Blades were hitting the U's on the counter attack and Walker pulled off a couple of good stops.
Kitson tested the U’s keeper with ten minutes to go, his low shot turned away by the feet of the stopper.