Although the versatile Dallas put them ahead after 42 minutes, the odds were quickly stacked against the Whites.
Captain Liam Cooper was dismissed following a VAR review in first-half stoppage time after a poor tackle on Gabriel Jesus. City piled on the pressure after the break but met with stubborn defence after Marcelo Bielsa reorganised his side.
They did finally register through Ferran Torres 14 minutes from time but, pressing for a winner, they were caught out by Dallas’s added-time breakaway, the Northern Ireland international firing low past the on-rushing Ederson to spark wild celebrations. Only City’s second defeat in 29 games in all competitions defied the statistics, with the quadruple-chasing hosts racking up 29 shots to Leeds’s two.
“I cannot believe it because all the team was very tired,” said Cooper’s central defensive partner Llorente.
“I don’t know where he (Dallas) got the energy but he got the goal and I am very happy for him and all the team.
“It was very nervous at the end but the team did a great effort.
“We knew that with the red card of Cooper it was going to be difficult but the team, in the second half, had a great attitude and did a great job. With the effort of the whole team, we got the victory.”
Leeds actually saw more of the ball than City in October’s reverse fixture, a 1-1 draw, which is almost unheard of against a Pep Guardiola team, but a man down for half the game, they settled for just 29 per cent on Saturday.
Crucially, though, they were not prepared to accept a draw against opponents who even after their surprise defeat are still likely to cruise to the title. With six games left, they need just 11 points.
“You should never give up,” said matchwinner Dallas. “Going down to 10 and they equalise – but we managed to find something. It is about how much you really want it.
“Against these teams you don’t get (many) chances, so you need to be clinical.
“I think I took one touch and closed my eyes.
“It is a great result for us.
“It was tough out there. It is hard enough with 11, never mind 10. We defended really well and kept them to very few good chances.
“We knew if we could have a bit more composure we could get one chance.
“You hope Raphinha going through is the one but I managed to get on the end of one.
“I saw it opening up. We came with a game plan but going down to 10 that changes.
“We dug in and showed a different side to us. We have been criticised about our defending but we stood up.”
Cooper was initially shown a yellow card for his tackle on Jesus which caught Manchester City’s Brazilian striker high on his leg. Andre Marriner changed his decision after following video assistant referee David Coote’s advice to consult the pitchside monitor.
“He won the ball but has left something on him,” said Dallas. “He gave the referee a decision to make, but we had to get on with it.”
While aspects of City’s game clearly frustrated manager Guardiola – a water bottle was thrown hard at the ground at one point – a thorough inquest is hardly likely.
Not only is the result unlikely to deny them a third title in four years, but they have other more pressing matters in their quadruple quest.
Wednesday sees them travel to Germany for the second leg of their Champions League quarter-final against Borussia Dortmund, which is finely poised at 2-1 in the English side’s favour.
City started slowly but were beginning to assert themselves, with Raheem Sterling spurning one particularly good chance, before Leeds grabbed the lead.
“We are obviously sad for the result but the good thing is we are still on top of the table, close to our objective,” said winger Torres.
“Now we just turn the page and focus on the Champions League game against Dortmund because it doesn’t stop. We want to be in the semi-finals of the Champions League.
“We know that Bielsa’s teams run a lot and are difficult teams to beat, and when they were down to 10 men they stayed back and made it difficult for us.
“We created a lot of chances but we couldn’t score,” added Torres.
Before the game, Leeds had only won once this season against the top seven clubs in the Premier League, away at Leicester City.
Their next three matches at Elland Road are all against England’s elite clubs. A week today they host Liverpool before welcoming Manchester United the following Sunday. Tottenham Hotspur come to West Yorkshire on May 8.
Victory moved Leeds back into the top half of the table with seven matches still to play but it was the manner of their victory and the strength of their opponents which should give them most heart for the run-in.
Manchester City: Ederson, Joao Cancelo, Stones, Ake (Gundogan 59); Mendy (Foden 74), Bernardo Silva, Fernandinho, Zinchenko, Torres; Gabriel Jesus, Sterling. Unused substitutes: Walker, Dias, Steffen, Rodri, De Bruyne, Mahrez,
Leeds United: Meslier, Ayling, Llorente, Cooper, Alioski, Phillips; Raphinha (Shackleton 90), Dallas, Roberts (Koch 63), Helder Costa; Bamford (Struijk 45). Unused substitutes: Poveda-Ocampo, Casilla, Hernandez, Berardi, Gelhardt, Klich.
Referee: A Marriner (West Midlands).
Support The Yorkshire Post and become a subscriber today. Your subscription will help us to continue to bring quality news to the people of Yorkshire. In return, you’ll see fewer ads on site, get free access to our app and receive exclusive members-only offers. Click HERE to subscribe.