Luke Ayling scored against his former side as Leeds eked out a gritty 1-0 win over Bristol City to go three points clear in the Championship automatic-promotion spots.
The defender lashed home early on but despite dominating the encounter, the hosts could not add to their tally.
Leeds would have been buoyed by leaders West Brom dropping points earlier in the day.
The Baggies were held by Nottingham Forest - and the win for Marcelo Bielsa's side trimmed the gap between the pair to four points, with Leeds three ahead of third-placed Fulham.
Leeds made an electric start and skipper Liam Cooper nodded wide from a corner after just two minutes.
Helder Costa then saw a near-post effort well stopped by Dan Bentley.
Bristol City were struggling to live with Leeds at times, but their patterns of good build-up play were without any end product - a familiar theme for Leeds this season.
The opener arrived in the 15th minute and it came after a mad scramble in the box.
Leeds were repelled on a number of occasions by excellent Bristol City defending but their resistance was finally broken when the ball fell kindly to Ayling.
Despite being surrounded by a mass of City defenders, Ayling smashed the ball past Bentley.
Leeds thought they had doubled their lead just a couple of minutes after, when Patrick Bamford tapped in after a shot had bounced kindly for him after striking the crossbar.
Unfortunately, the flag was raised immediately as Bamford was offside.
Undeterred, Bamford then flashed a shot at goal after a superb control and spin.
City started brightly after the restart and were appealing for a penalty after Ayling blocked a shot in the area.
Referee Tim Robinson was uninterested despite the vocal appeals from City boss Lee Johnson and his coaching staff.
Jack Harrison was catching the eye in particular and he whipped in a dangerous centre that only just evaded the onrushing Costa.
Chances were coming thick and fast for the hosts going into the final quarter of the game and when Costa laid it on a plate for Bamford he looked destined to make it 2-0.
Somehow though, he saw his shot from a few yards kept out by the agile Bentley.
A minute later Bentley made an even more scarcely-believable save.
Costa latched onto a long pass and rounded Bentley only for the City keeper to somehow stick out a hand and divert it behind for a corner.
Leeds were bossing the match and chances continued to come and go for the Whites.
The impressive Harrison, who was a menace down the left flank all afternoon, thought he was the one to finally seal the second goal but his speculative effort came back off the crossbar.
Substitute Jean-Kevin Augustin, with almost the last kick of the game, placed a shot just wide but the hosts' profligacy was unpunished as they held on.
What the managers said...
Leeds' Marcelo Bielsa: "I feel we have more resources to manage the different kinds of matches. But I cannot forget this season we were winning 3-0 and drew the match (against Cardiff).
"This was a fair win. We attacked well, we missed a lot of chances. But we defended well and they created few chances. The performance, in general for the team, was positive."
Bristol City's Lee Johnson: "I thought that Leeds were the better side throughout. In the first 15/20 minutes we didn't accept that we needed to do certain things and have a bravery to go at the game. At half-time I wasn't best pleased. That's not discrediting Leeds because they were very good. We just didn't play like I want us to play.
"We did, for most parts of the second half, and I thought we made a game of it. We've just got to be better against the top teams."