Two first-half goals from Samuel Saiz set Leeds on course for a 3-0 Championship win at Bristol City.
Pierre-Michel Lasogga completed a convincing and overdue victory with a second-half header before both sides were reduced to 10 men as Leeds full-back Gaetano Berardi and City substitute Matt Taylor were shown red cards for a 79th-minute confrontation. Taylor went down clutching his face, but was judged equally guilty and the incident sparked trouble between the two benches, with stewards getting involved.
Going into the match on a three-game losing streak in the Championship, Leeds needed a good start to boost confidence. They got it on four minutes when Lasogga got between City's centre-backs and slid the ball into the path of Saiz, whose right-footed shot from inside the box appeared to take a deflection past Frank Fielding.
The CIty goalkeeper was exposed again 10 minutes later and chose to make a challenge with his feet only for the ball to run into the path of Saiz, who fired home from 12 yards. The impressive Lasogga completed the scoring on 67 minutes, capitalising on poor marking to head home a Kalvin Phillips corner.
Leeds were dominant from the opening whistle and out-battled their hosts, Saiz and Lasogga both shooting wide in a sharp opening. It was not until City were 2-0 down that they fashioned a chance, top scorer Bobby Reid heading wide from a Callum O'Dowda cross.
Without injured midfield driving force Korey Smith because of injury, Lee Johnson's men lost the battle in the centre of the park and came under consistent pressure. Referee Oliver Langford rejected first-half penalty appeals by the home side when Jonathan Leko and Joe Bryan went tumbling inside the box, but City could have no complaints about the scoreline.
Backed by massed ranks of travelling fans behind one goal, Leeds were good value for their half-time advantage even though O'Dowda had a fierce shot blocked just before the break.
The visitors also began the second half on the front foot, with Phillips heading over from a Ezgjan Alioski cross. When Lasogga had a long-range shot saved by Fielding, Johnson had seen enough and sent on Famara Diedhiou and Matt Taylor for Leko and Cauley Woodrow.
The game should have been over as a contest before the hour mark as Saiz shot wide of an open goal from Ronaldo Vieira's pass and Lasogga had a shot cleared by Aden Flint. Jens Hegeler was booked for an embarrassing shirt-pull on Vieira as City continued to look vulnerable at the back.
Then came Lasogga's goal and Hegeler was immediately replaced by Hordur Magnusson. The sendings-off sparked a frantic finish, which saw Diedhiou head badly wide to complete City's misery.
The managers
Lee Johnson: "I have seen the incident again and as far as I am concerned Matty was blameless other than to register a complaint over being fouled. My player has a broken nose so it was a nasty clash. We will definitely appeal the decision and I think the film evidence backs our case.
"Overall, it was a bad day at the office for us. We were weak today and that is not usually the case. We were off it in the first 20 minutes and that's is when the game was decided. Some key players were missing through injury and illness, but those selected were capable of better. Now we face Crystal Palace in the Carabao Cup on Tuesday night and need to get back to form quickly."
Thomas Christiansen: "Our thoughts are with Stewy (Stuart Dallas] and we wanted to put in a performance for him following the bad news that his mother had passed away. On behalf of myself, the players and staff, we send our condolences and assure him that this win was for him. I was very happy with the performance of the team. It is the same players who put us in the position we were in going into the match and today the difference was the intensity of our play.
"We knew we were up against a good side and that probably helped. We needed to be brave and believe in ourselves. The early goals were important and today we took our chances, whereas in other games we should have been ahead, but failed to score when we might have."