After Sheffield United had earlier been pegged back by a stoppage time equaliser from Millwall at Bramall Lane, Marcelo Bielsa’s men responded in the perfect fashion to beat Sheffield Wednesday and open up a three point advantage over their main rivals.
Jack Harrison got the only goal in the 65th minute, the Manchester City loanee turning in a Pablo Hernandez cross.
But, in reality, Leeds should have won by a far more convincing margin after dominating a keenly-fought derby clash.
Keiren Westwood largely stood between United and what would have been a timely boost to their goal difference with a string of fine saves.
Gary Hooper also cleared off the line during the first half and Steve Bruce’s men could have little complaint at returning down the M1 with nothing to show for their efforts.
Wednesday gave everything. Tom Lees, despite being booked early on, and Michael Hector were tireless in their efforts but Leeds’ crisp passing game meant that the best side won.
Tyler Roberts went close to breaking the deadlock three times in the first half.
First, he rose high above the Owls defence to meet a corner only for his header to be brilliantly saved by Keiren Westwood.
Then, after collecting a pass from Patrick Bamford, he curled a 25-yard shot agonisingly wide of the post.
Finally, Roberts brought down a Bamford cross before firing a shot that Westwood blocked. His follow-up effort then flashed across goal.
Gary Hooper also blocked a Luke Ayling shot on the line during an entertaining first half that saw Barry Bannan’s 25-yard curling effort touched round the post by Kikop Casilla at full stretch.
Bamford had a chance early in the second half, the United striker showing great inventiveness to head the ball just wide after his initial effort had been blocked by Tom Lees.
Ezgjan Alioski then had a 25-yard shot that just cleared Westwood’s crossbar before Patrick Bamford wasted a glorious opportunity when side-footing wide from two yards out.
It was a big let-off for the Owls but not one they were able to capitalise on, the hosts going in front just a couple of minutes later.
Jack Harrison was the man to guide the ball past Westwood after being picked out by Pablo Hernandez’s drilled pass.
Wednesday had been second best all game but they did have one late chance, Marco Matias firing into the side-netting after an earlier effort from Fernandeo Forestieri had been charged down.