Sheffield United recorded a huge 1-0 win away against Yorkshire rivals Leeds United to move above them and into the automatic promotion positions.
Chris Basham was the unlikely hero for Sheffield United to prove the difference on the day as he netted his fourth goal of the season to put the visitors ahead in the 71st minute.
Leeds had plenty of chances to go ahead, but were left rueing them as Sheffield United put in a well-organised defensive shift to deny them.
Story of the match
With the game underway after a particularly loud rendition of 'Marching On Together' from the sell-out Elland Road crowd, Leeds took a few minutes to shake off the nerves with some errant passing in the early stages.
But they soon took control, setting the tempo in the opposition half and dominating the ball. Pablo Hernandez, so often Leeds best player this season, was particularly lively in his wide playmaker role, and it was he who created Leeds best opportunity of the opening half when he beat the offside trap, darted to the byline and cut a good ball in to Patrick Bamford, but Martin Cranie blocked the striker's shot well.
Cranie had come in to the back three and put in a solid performance as Blades boss Chris Wilder opted for extra brawn in midfield by moving Basham further forward into midfield. The gameplan looked to be to sit back and nullify Leeds, and while the hosts created half chances to score, it was a largely successful approach in the first half. They'd kept a clean sheet in each of their last six matches and looked confident in their ability to extend that run.
Sheffield United were physical and dogged, coming to Elland Road for a battle in the wind and rain as they were determined not to allow Leeds to pull further away in 2nd. This was an effective approach, but a robust, late challenge from George Baldock on Pontus Jansson midway through the first half was close to the line and might have resulted in a red card rather than a yellow one.
Billy Sharp, who had scored seven goals in eight games against Leeds before this, was largely isolated but looked satisfied to battle for scraps. This approach eventually paid dividends as the visitors grew into the game and started to test Leeds before the break, putting hearts in mouths with a series of corners.
The second half continued in a similar tone, and Leeds came close as Tyler Roberts hit the post, but it was Sheffield United that opened the scoring as Sharp broke forward, pounced on dalliance from Liam Cooper, and squared it to Basham who slotted past a helpless Kiko Casilla.
Marcelo Bielsa responded by bringing on Jack Clarke, for his first appearance since being hospitalised with a virus against Middlesbrough a month ago, and Stuart Dallas, but Leeds were unable to fashion a breakthrough.
Jansson, who become a makeshift centre-forward, was inches from levelling in the 86th minute. The Swedish centre-half was limping and lacked the mobility to carry on in the backline, but Bielsa had made all three substitutions and he was in the right place to swing a leg at Clarke's drilled pass into the six-yard box.
The breakthrough never came though, and things went bad to worse for Leeds as Casilla was sent off for a last-man challenge on Sharp in injury time. Jansson, who had played both as a defender and a striker, and had to change a bloodied shirt once already, then became goalkeeper for the final few minutes but was never called into action.
Takeaways from the match
All to play for in the final run-in
Just one point separates Sheffield United and Leeds now, as the season approaches the final run-in. There are just eight games left to play once the Championship season resumes following the international break.
Both teams have similar run-ins, with tricky trips to Birmingham and Preston for both. Leeds will consider this a real missed opportunity to go five points clear in second, but they're only one point behind with everything to play for.
Sheffield United's defence might just see them promoted
The Blades created very few chances against Leeds, but taking just one was enough for them to come away with three points - and this could well become a recurring theme as the season nears the end.
For large parts of the season, Sharp's goals had fired them to victories - but now Gary Madine is serving a suspension, Sharp and McGoldrick have one goal between them in the last seven games, and Scott Hogan hasn't impressed with recent opportunities.
But that's not a problem when one goal, by hook or by crook, is enough to get them to victory. It's now seven consecutive clean sheets for Sheffield United.