Tottenham Hotspur got off to the ideal start as Son was on the scoresheet within five minutes, thanks to a lovely looped pass by Tanguy Ndombele.
The South-Korean star timed his run to perfection and caught the City defenders napping. He rolled the ball through Ederson's legs, after the Brazilian goalkeeper moved off his line a second too early.
City dominated the proceedings from that point onwards and thought they had equalised through Aymeric Laporte in the 25th minute. However, it was ruled out on account of handball after a long VAR consultation.
Gabriel Jesus had put his arms out before making the pass to the French defender, and the decision did not go down well with the visiting players.
Interestingly, Tottenham Hotspur recorded no shots on target after scoring through their first attempt. Meanwhile, the visitors knocked at their door with shots 11, finding the target three times before the break.
Manchester City could not keep up their intensity after the break. They were yet again caught on the counter-attack by the hosts, as Lo Celso went on to beat Ederson from a similar position than Son.
Tottenham Hotspur continued to frustrate City with their no-nonsense defending and the visitors, even after 22 attempts, could not beat Hugo Lloris.
Here are the five talking points from the game, as Jose Mourinho recorded back-to-back wins in league fixtures against Pep Guardiola for the first time in 24 attempts.
#5 Son Heung-min can't stop scoring for Tottenham Hotspur
Tonight, it took only one shot and five minutes for Tottenham Hotspur's prolific forward Son Heung-min to make the net bulge against Manchester City.
Son has scored nine goals in the Premier League this season, which puts him right at the top of the scoring charts. Jamie Vardy and Dominic Calvert-Lewin, both on 8, are yet to play their fixtures this weekend.
It was Son's second goal in as many games against Pep Guardiola's men and it seriously seems like he will give Harry Kane a run for his money for the Golden Boot award this term.
#4 Jose Mourinho's parking the bus much more effectively
Dull, monotonous and predictable... that's how Jose Mourinho's infamous "Park The Bus" tactic has been described in the past.
Well, the kind of football Tottenham Hotspur have played this season has been anything but that. Mourinho's side have scored 20 goals in nine games this term, second best only to Chelsea, who have 22 in the league.
It seems the Portuguese manager has refined his modus operandi since taking over the reins at the North London club, and now focuses on drawing first blood. In their last 10 outings, Tottenham Hotspur have scored the first goal in eight of them, which has allowed them to take control early on.
Against City, Tottenham took the lead just five minutes after kick-off and were happy to sit back, defend and only attack on the counter after that. They defended well and put in some really well-timed tackles to halt City's ingress in the final third.
It seems Mourinho has learned how to parallel park the bus and as long as he's churning out results, no one will bat an eyelid.