Arsenal maintained their position at the Premier League summit as an outstanding display overpowered Tottenham in the north London derby at Emirates Stadium.
Mikel Arteta's side were superior throughout and Spurs' cause was not helped by Emerson Royal's red card for a second-half foul on Gabriel Martinelli.
Arsenal made a fast start and took a deserved lead when Thomas Partey side-footed a precise finish into the top corner from 25 yards after 20 minutes.
Spurs were handed a lifeline before the break when Gabriel's foul on Richarlison gave Harry Kane the opportunity to score his 14th goal in 18 derby games and his 100th goal away from home in the Premier League from the penalty spot.
Arsenal were gifted the lead once again when Spurs keeper Hugo Lloris fumbled badly to allow Gabriel Jesus to score four minutes after the break, Antonio Conte's frustration made worse by Royal's reckless challenge on Martinelli that prompted referee Anthony Taylor to produce a straight red card.
Conte was attempting to make three changes when Granit Xhaka effectively ended the contest with a low finish past Lloris from inside the area.
Arsenal growing in stature
Arsenal's outstanding start to the season, aided by some smart work in the transfer market in the summer, has raised hopes that they might be coming out of a long period of post-Arsene Wenger transition.
The Gunners were bitterly disappointed to miss out on Champions League football on the final day of last season but there is an energy, verve and threat about Arsenal that suggests they can make a serious impact in this campaign.
Even in defeat at Manchester United last month, Arsenal showed signs of maturity and progress, emphasised here by the manner of their victory over the old rivals.
Arsenal flew out of the blocks to take the lead and even recovered from the frustration of handing an out-of-sorts Spurs a route back into the game via Gabriel's challenge on Richarlison.
Jesus has proved to be a superb signing, while William Saliba has been outstanding in central defence since returning from loan spells at St Etienne, Nice and Marseille.
There is still work to be done but Arsenal look like a club and a team who finally have a clear direction again, a mouth-watering mix of younger players and experience that bodes well for the future.
Arsenal's next game, here against Liverpool next Sunday, will be another significant test but there is growing confidence around Emirates Stadium.
Spurs fall badly short
Spurs may argue over the merits of Emerson Royal's red card but it was a poor challenge in a position where he actually had no need to engage with Martinelli. Spurs manager Conte was instantly infuriated by the challenge itself although he was clearly not expecting the punishment that followed.
Conte's side have not been pleasing on the eye this season but they have been digging out results until this first Premier League defeat of the campaign.
Spurs had a spell of threat after Kane's penalty, and indeed the game's first big chance when Arsenal keeper Aaron Ramsdale blocked Richarlison, but they were lacklustre and dominated in all areas.
There was no coming back after the sort of inexplicable mistake Lloris, for all his big reputation, can be guilty of committing, and Royal's red card only pushed any prospect of even a point further into the distance.
Kane and Son Heung-min, who was later substituted along with Richarlison - Conte was trying to make three changes when Xhaka scored Arsenal's third - could not get into the game.
Spurs were well beaten long before the end, Conte cut a resigned figure in his technical area and this was another miserable north London derby away day for manager, player and supporters.
Player of the match
Gabriel MartinelliGabriel Martinelli
9Gabriel Jesus1Ramsdale4WhiteSubstituted forTomiyasuat 89'minutes12SalibaBooked at 78mins6Gabriel35ZinchenkoSubstituted forTierneyat 73'minutes5ParteySubstituted forSambi Lokongaat 73'minutes34Xhaka7Saka8ØdegaardSubstituted forFerreira Vieiraat 80'minutes11MartinelliBooked at 85mins9Gabriel JesusSubstituted forNketiahat 80'minutes
Substitutes3Tierney14Nketiah16Holding18Tomiyasu21Ferreira Vieira23Sambi Lokonga24Nelson27Oliveira Alencar30Turner
10Kane1Lloris17Romero15DierBooked at 90mins34LengletSubstituted forD Sánchezat 71'minutes12Emerson RoyalBooked at 62mins5HøjbjergSubstituted forSkippat 75'minutes30Bentancur14PerisicSubstituted forBissoumaat 71'minutes9RicharlisonSubstituted forR Sessegnonat 71'minutes7Son Heung-MinSubstituted forDohertyat 72'minutes10Kane
Substitutes2Doherty4Skipp6D Sánchez11Gil19R Sessegnon20Forster24Spence29Sarr38BissoumaReferee:Anthony TaylorAttendance:60,278
Match ends, Arsenal 3, Tottenham Hotspur 1.
Second Half ends, Arsenal 3, Tottenham Hotspur 1.
Attempt missed. Gabriel Martinelli (Arsenal) right footed shot from a difficult angle and long range on the left is just a bit too high from a direct free kick.
Eric Dier (Tottenham Hotspur) is shown the yellow card for a bad foul.
Eddie Nketiah (Arsenal) wins a free kick on the left wing.
Foul by Eric Dier (Tottenham Hotspur).
Eddie Nketiah (Arsenal) wins a free kick in the attacking half.
Foul by Eric Dier (Tottenham Hotspur).
Attempt blocked. Fábio Vieira (Arsenal) left footed shot from the centre of the box is blocked.
Corner, Arsenal. Conceded by Hugo Lloris.
Attempt saved. Kieran Tierney (Arsenal) left footed shot from outside the box is saved in the bottom right corner. Assisted by Fábio Vieira.
Substitution, Arsenal. Takehiro Tomiyasu replaces Ben White.
Gabriel Martinelli (Arsenal) is shown the yellow card for a bad foul.
Foul by Gabriel Martinelli (Arsenal).
Matt Doherty (Tottenham Hotspur) wins a free kick in the defensive half.
Substitution, Arsenal. Eddie Nketiah replaces Gabriel Jesus.
Substitution, Arsenal. Fábio Vieira replaces Martin Ødegaard.
Attempt blocked. Harry Kane (Tottenham Hotspur) right footed shot from outside the box is blocked. Assisted by Eric Dier.
William Saliba (Arsenal) is shown the yellow card for a bad foul.
Foul by William Saliba (Arsenal).Our coverage of your Premier League club is bigger and better than ever before - here's everything you need to know to make sure you never miss a moment