Tottenham moved top of the Premier League after strikes from Son Heung-min and Giovani Lo Celso earned them a statement 2-0 victory over Manchester City.
Jose Mourinho celebrated a year in charge of Spurs with a second straight win over old rival Guardiola, who was hoping to mark his new contract with a positive result but has now lost all three of his games at Tottenham Hotspur Stadium.
Son converted a Tanguy Ndombele pass after five minutes on Saturday and Mourinho's men, who spent much of the intervening time on the back foot, sealed the triumph when Lo Celso beat Ederson with 25 minutes remaining.
Aymeric Laporte had a first-half goal ruled out for City and they are now eight points behind Spurs, who ended Chelsea's brief stint at the top of the table.
Spurs made an excellent start when a lofted ball from Ndombele found Son, who beat the offside trap and took one touch with his right foot before sending a cool finish with his left through the legs of an onrushing Ederson.
Harry Kane had the ball in the net after a superb move involving Son, only to be denied by an offside flag.
Aside from those incidents, City controlled proceedings with Ferran Torres, Rodri and Ruben Dias all forcing routine saves from Spurs goalkeeper Hugo Lloris.
The visitors thought they had levelled the contest after 27 minutes when Laporte fired in, only for referee Mike Dean to overturn the goal after viewing the monitor, having found Gabriel Jesus handled Rodri's cross before passing to the defender.
City continued to probe without creating a notable opportunity before a swift Spurs counter-attack saw Kane thread a pass through to Lo Celso, the substitute hitting a fine left-footed finish beyond Ederson just 35 seconds after replacing Ndombele.
Guardiola threw on England duo Phil Foden and Raheem Sterling with 18 minutes left but Lloris saved from Dias late on as Spurs held on for a memorable victory by the same scoreline as they won this fixture in February.
What does it mean? City continue to struggle
City had 11 shots to Spurs' one in the first half and 68.7 per cent of the possession, and by the end of the game had won the shot battle 22-4.
But it was a familiar story for City to many of their away defeats since the start of last season, with just five of their efforts finding the target and their play becoming increasingly less threatening as the match went on.
They have netted 10 league goals in eight games and just five in their last six. We now know Guardiola is staying and he knows there is a lot of work to do.
Kane puts Spurs into title race
Kane's assist means he has now been involved in 24 goals in just 15 games across all competitions this term.
His all-round play has been superb all season and his fine pass for Lo Celso was one of 22 he completed in the opposing half, a team high.
It is still early in the season, but four consecutive league wins for the first time since February 2019 mean Spurs are firmly in the title race.
Familiar failings for City
The positioning of Rodri, Joao Cancelo and Laporte can be called into question for Son's opener, while Ederson charged out of goal on both occasions, though perhaps of greater concern is City's attacking play.
Jesus and Kevin De Bruyne did not find the target from 10 combined attempts, while Torres had just one key pass as he was unable to match his fine display for Spain. The return of Sergio Aguero, an unused substitute in this one after a month out injured, cannot come quickly enough.
Key Opta Facts
- Tottenham have won back-to-back league games against Manchester City for the first time since a run of three between September 2015 and October 2016.
- Spurs will finish a day top of the Premier League table for the first time since August 2014, while it is the first time they will end a day top of the top flight after at least nine games into a season since January 1985.
- A return of 12 points from eight games marks City's lowest points total at this stage of a Premier League campaign since 2008-09 (10), while 10 goals is their lowest tally after eight games since 2006-07 (6).
- City have had 41 shots across their last two Premier League games against Spurs, losing them both without scoring. Meanwhile, Spurs scored with both of their shots on target in this match.
- Spurs have scored more goals in the first half of Premier League games than any other side this season, with their 11 in the opening 45 minutes being more than City have netted overall (10).
Tottenham host Ludogorets in the Europa League on Thursday before a massive top-of-the-table clash against Chelsea at Stamford Bridge on Sunday. City look to bounce back in in Greece as they play Olympiacos in the Champions League on Wednesday and return to top-flight action at home to Burnley three days later.