Match ends, Leeds United 2, Birmingham City 0.
Goals from Samuel Saiz and Stuart Dallas helped Leeds beat Birmingham City to move top of the Championship.
Saiz tapped in the rebound from a yard out after David Stockdale had saved Pierre Michel-Lasogga's fierce strike.
City full-back Maxime Colin had a header cleared off the line just before the break, while Stockdale reacted brilliantly to deny Lasogga.
Birmingham created a number of chances, but Dallas secured three points for the hosts with a late left-footed strike.
Harry Redknapp's Blues could consider themselves unfortunate not to have taken a point from the game, with Michael Morrison and Sam Gallagher both going close to scoring in the first half.
Jason Lowe also had a goal correctly ruled out for offside in the second period as Birmingham fell to a fourth successive league defeat.
Leeds' resilience saw them extend their unbeaten start to the season to nine games, while goalkeeper Felix Wiedwald has kept clean sheets in each of his past six league games.
Saiz's opening goal was his sixth in eight games since joining Leeds from SD Huesca in July, and the Spaniard could have made the points safe earlier, only to be denied by another fine Stockdale save.
Instead it was left to Northern Ireland international Dallas to settle Leeds' fans nerves with his his first goal at Elland Road since March 2016.
Leeds manager Thomas Christiansen:
"If you tell me it's the last game and we're in that position [first place] I would be happy, proud and all that you can say about that.
"But right now, don't give me anything. It puts a bit more pressure on the team because everyone now wants to beat Leeds.
"The performance was not the best, but if you still take the three points you have to be proud. What we have done until now is a high level."
Birmingham manager Harry Redknapp:
"We completely dominated the second half. It was one-way traffic, wasn't it?
"We just couldn't get a break when we needed it and then obviously, we're pushing six forwards up the pitch to try and get a goal and you get done on the counter-attack.
"I've got a new team. I changed a team that wasn't good enough, but I didn't get them in for the start of the season. People need to be patient. They've got players here now who can take them on to another level."
- 6CooperSubstituted forBerardiat 69'minutes
- 23PhillipsBooked at 79mins
- 10AlioskiSubstituted forRoofeat 60'minutes
- 19HernándezSubstituted forDallasat 80'minutes
- 28MorrisonBooked at 90mins
- 21LoweBooked at 73mins
- 27JotaSubstituted forWalshat 80'minutes
- 26DavisSubstituted forMaghomaat 80'minutes
- 18GallagherBooked at 53minsSubstituted forAdamsat 69'minutes
- Peter Bankes
- Shots on Target
Second Half ends, Leeds United 2, Birmingham City 0.
Corner, Leeds United. Conceded by Michael Morrison.
Attempt blocked. Vurnon Anita (Leeds United) right footed shot from outside the box is blocked. Assisted by Pierre-Michel Lasogga.
Michael Morrison (Birmingham City) is shown the yellow card for a bad foul.
Goal! Leeds United 2, Birmingham City 0. Stuart Dallas (Leeds United) left footed shot from the right side of the box to the bottom right corner. Assisted by Pierre-Michel Lasogga.
Corner, Birmingham City. Conceded by Pontus Jansson.
Harlee Dean (Birmingham City) wins a free kick in the attacking half.
Foul by Pierre-Michel Lasogga (Leeds United).
Foul by Cheikh Ndoye (Birmingham City).
Kalvin Phillips (Leeds United) wins a free kick in the defensive half.
Foul by Maxime Colin (Birmingham City).
Kemar Roofe (Leeds United) wins a free kick on the right wing.
Offside, Birmingham City. Cheikh Ndoye tries a through ball, but Che Adams is caught offside.
Jason Lowe (Birmingham City) wins a free kick in the defensive half.
Foul by Samuel Sáiz (Leeds United).
Attempt saved. Liam Walsh (Birmingham City) right footed shot from outside the box is saved in the centre of the goal. Assisted by Jeremie Boga.
Substitution, Leeds United. Stuart Dallas replaces Pablo Hernández.
Substitution, Birmingham City. Liam Walsh replaces Jota.
Substitution, Birmingham City. Jacques Maghoma replaces David Davis.