The Citizens travelled to the Tottenham Hotspur Stadium having failed to win their previous four visits without scoring, but they knew that a victory would keep the title race in their own hands heading into the final day of the season.
Both sides cancelled each other out during a subdued first half, but Man City broke the deadlock six minutes after the interval when assist king Kevin De Bruyne teed up Erling Haaland for a simple ta-pin.
Spurs responded well and should have netted a late equaliser, but City's substitute goalkeeper Stefan Ortega, who replaced the injured Ederson in the second half, made an enormous save - a title-clinching stop - five minutes from time to deny Son Heung-min, who had bust clean through on goal.
Within the blink of an eye, Man City were awarded a penalty at the other end after Pedro Porro tripped Jeremy Doku, allowing Golden Boot-chasing Haaland to emphatically net his second and secure three hugely important points for the visitors.
Victory for Pep Guardiola's side has helped them climb back to the top of the Premier League table, sitting two points clear of title rivals Arsenal heading into their final fixture of the campaign at home to West Ham United on Sunday.
The result also means that Aston Villa have qualified for the Champions League at Tottenham's expense, as defeat for Ange Postecoglou's men leaves them in fifth spot and five points behind Villa in fourth with only one game remaining.
Cagey first half amidst a tentative Spurs atmosphere
There was a real zip to the passing and pressing of both teams in the early exchanges, and it was Spurs who had the first sight at goal, but a strong hand from Ederson - making his 250th Premier League appearances - kept out a powerful strike from Rodrigo Bentancur.
Man City were then gifted their first chance of the evening following a catalogue of defensive errors form the hosts. Both Radu Dragusin and Cristian Romero failed to clear their lines before Pierre-Emile Hojbjerg's horribly mis-timed clearance fell straight to Phil Foden, but his volley from around 10 yards out was kept out by a fantastic reflex save from Guglielmo Vicario with his outstretched right arm.
Former Spurs man Kyle Walker posed the greatest attacking threat for Man City in the opening half-hour and found lots of space down the right flank with Micky van de Ven, playing as an inverted left-back, often tucking inside. Walker fizzed a few dangerous deliveries into the penalty area, but he was able to pick out a teammate on each occasion.
Guardiola was cut a frustrated figure at times as his Man City side were surprisingly sloppy in possession, but to their relief, Spurs lacked an end product and rarely threatened Ederson's goal despite showing signs of promise in the final third.
Man City grew in confidence towards the end of the half and were denied twice in stoppage time, with Haaland's close-range strike blocked by Van de Ven before Bernardo Silva fired the rebound straight at the head of Dragusin standing just a few yards off the line. Neither goal would have stood, though, as the linesman's flag was raised for an offside in the build-up.
More to follow.