Sheffield United's Iliman Ndiaye has his No 9 moment to calm Championship play-off nerves

But the captain was not even on the pitch when Iliman Ndiaye combined with his makeshift striker parnter Morgan Gibbs-White to bullet a header past Dillon Phillips and relieve the tension that was building at Bramall Lane.

It would be a crucial few minutes in the race for what looks just one Championship play-off place still up for grabs.

Just before Ndiaye's goal, chasers Middlesbrough went into the lead at Swansea City. Within a couple of minutes, the Blades were ahead, in-form Millwall behind and Swansea back on level terms.

Millwall ended up dramatically drawing 2-2 and the score at Swansea remained unchanged. Despite all the second-half pressure the home side applied, so did the one at Bramall Lane.

Sharp might have had a penalty as soon as he came on and Sander Berge hit a post in stoppage time but the details did not matter, only the outcome. Paul Heckingbottom's side remaining sixth with games running out for those who hope to catch them.

Three minutes after half-time, the goal was a classic in a game that was not.

Matches at this time of year are often too tense to be of the highest quality but the goal that decided this one was an exception to the rule, Gibbs-White peeling wide from the centre-forward position which is not his natural habitat and producing an excellent cross for Ndiaye - another more suited to the hole behind than the sharp end - to thump a header in.

If anyone was hoping a Cardiff side with little but pride to play for would roll over at that point, they were to be sorely disappointed and even when Sharp came off the bench in the 70th minute, his team could not find a second goal.

Even after the first, the nerves jangled at Bramall Lane. With only one win and three goals in their last five games, the Blades were wobbling, it was just that many of the teams around them were too.

Chris Basham did nothing to calm them, dribbling past Jordan Hugill at his own byline inside two minutes but the veteran's calmness was not mirrored elsewhere.

Max Watters beat John Egan too easily but was unable to beat Wes Foderingham, who later gave the ball straight to the striker, only for Cardiff to fail to make the most of his generosity.

When Hugill beat Jack Robinson too easily and Cody Drameh did the sam to Enda Stevens, it was Egan, then Robinson, who came across to tackle. But Foderingham would err again, tipping a Drameh cross into danger. Yet again, Cardiff failed to capitalise.

Slowly, though, the Blades began to crank into life higher up the field, usually when Gibbs-White or Berge were on the ball.

The first save, though, was forced by a fierce left-footed shot from Ben Osborn in the 14th minute.

Gibbs-White played an excellent ball to Berge in the 20th minute and the Norwegian controlled it well but by the time it came down, he was too close to Dillon Phillips to beat him.

Phillips denied Berge again from close in after a right-wing cross, and got a fingertip on his shot across goal.

Sharp's introduction for the injured Ndiaye got exactly the reception you would expect and as he controlled a Gibbs-White pass on his chest with his first touch of the game, Cardiff substitute Mark McGuinness appeared to shove him in the back. Referee Oliver Langford saw it differently.

For all the pressure that followed, there was not too much for Phillips to do but he was helpless when a lovely pass picked out Berge, who serenely stroked a shot onto the wodwork in the third added minute.

It was never going to be an easy win, but any win will do.

Sheffield United: Foderingham; Basham, Egan, Robinson; Osborn, Berge, Norwood, Fleck, Stevens; Gibbs-White, Ndiaye (Sharp 70).

Unused substitutes: A Davies, B Davies, Hourihane, Uremovic, Osula, Norrington-Davies.

Phillips; Ng, Nelson, Denham; Drameh (McGuinness 46, Ralls (Vaulks 46)), Wintle, Doyle, Bagan; Hugill, Watters (Colwill 66).

Unused substitutes: Flint, Ikpeazu, M Harris, Luthra.

Referee: O Langford (West Midlands)