Match ends, Arsenal 2, Tottenham Hotspur 0.
Arsenal closed to within a point of Tottenham and maintained their arch-rivals' miserable record at Emirates Stadium with a comfortable north London derby victory.
The pressure was on Arsene Wenger and the Gunners as they trailed Spurs in the Premier League table - but they responded in style and were superior in all areas of the pitch to win with plenty to spare.
Shkodran Mustafi headed a free-kick powerfully past Spurs keeper Hugo Lloris in the 36th minute after referee Mike Dean had contentiously penalised Davinson Sanchez for a challenge on Alexis Sanchez. The German defender also looked to have been offside.
Spurs manager Mauricio Pochettino said: "I do not need to say anything. It was obvious for everyone here and watching at home. It is not easy to accept because we lost the game but we have to move on and keep going.
"The free-kick for the first goal and the first goal was obvious offside, maybe the second was too. When you play against a team in the top six, the big details are up to you. Sometimes things go against you but that is football.
Wenger added: "The free-kick was a free-kick for me. We have had bad luck away from home - I'll leave that to the specialists."
Arsenal's domination was underlined five minutes later when Sanchez finished emphatically at the near post, effectively securing the Gunners' first league win over Spurs since 2014.
Tottenham - who have only once in 12 league visits to the Emirates - suffered with Harry Kane, looking well short of match fitness after missing England's friendlies against Germany and Brazil with a hamstring injury, rarely threatening, although Arsenal keeper Petr Cech saved athletically from Eric Dier's late header.
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Big three deliver for Wenger
Wenger has mysteriously often decided against using Ozil, Lacazette and Sanchez as a potent three-pronged attack this season.
This was only the third time he has used the three players together and the combination's potential and threat was obvious as Spurs were outplayed for most of this north London derby.
It also begged the question why it was not used - with £52m Lacazette the most obvious victim of Wenger's selection policy - in the 4-0 thrashing at Liverpool and the 3-1 loss at Manchester City earlier this season.
The France striker is already a popular figure among Arsenal fans, as proved by the fierce jeering when he was replace by Francis Coquelin with 17 minutes left, while Sanchez and Ozil have long been providing the attacking class for the Gunners.
Sanchez can be high maintenance and Ozil mercurial, but the three were at Spurs' throats from the start, providing fluidity and danger the visitors found almost impossible to control.
Lacazette and Sanchez were central figures in the crucial second goal, lashed into the roof of the net from an angle by the Chile international.
And Ozil, the languid and elegant German, was full of energy and creation.
This outcome will surely have crystallised Wenger's thoughts on the matter - Arsenal are a much more complete and threatening proposition with the three together than without them.
Spurs fall short again
Tottenham rightly received all the plaudits for a magnificent demolition of holders Real Madrid in the Champions League at Wembley - but a pattern is emerging that must be of concern to manager Pochettino.
Pochettino's side came up short in a hard-fought match at Manchester United last month - and were miles off the expected standard as they slumped to a loss they can have few complaints about at their arch-rivals on Saturday.
Spurs' last win away at a fellow member of what might be termed the Premier League's 'big six' came with a 2-1 victory at Manchester City on 14 February 2016.
The Emirates has been a grim place for Tottenham to come to, with only one win in 12 visits with seven defeats - a statistic they never looked like changing here.
There was little doubt captain and main marksman Kane, who wore a large strapping on his right leg after missing England's friendlies against Germany and Brazil with a hamstring injury, was short of match fitness and Alli made no impact.
Pochettino's main worry will surely be that the drive, intensity and pressing he regards as a hallmark of the Spurs style all belonged to Arsenal on this occasion.
Yes, Tottenham can complain they were harshly dealt with for the first goal - but they were very much second best and this is something Pochettino will have to change if they are to make that elusive leap from runners-up to Premier League champions.
Dean the villain for Spurs
The appointment of Mike Dean as referee for this north London derby created much debate among Arsenal supporters, who feel they have been on the rough end of decisions from the official in the past.
And some of Dean's early adjudications brought howls of outrage from Gunners fans - but in the end it was Spurs who were left complaining after a contentious decision led to the opening goal.
Dean punished Sanchez for what looked like a legitimate challenge, the resulting free-kick being headed past Lloris by Mustafi.
Arsenal boss Wenger was furious about the standard of officiating after the 3-1 loss at Manchester City on 6 November, saying after a third goal that replays showed was offside: "I feel referees don't work enough. The level drops every season at the moment and overall it's unacceptable."
On this day, however, Pochettino was the manager with cause for complaint.
Man of the match - Mesut Ozil (Arsenal)
'Perfect performance from Arsenal'
Former England captain Alan Shearer on BBC Match of the Day:
Arsenal must frustrate the hell out of their own support. They can perform like they did today and should do it more often.
I criticised them a few weeks ago for their performance against Manchester City but they were brilliant at their pressing game today. They got it perfect. Against City they went as ones and twos. Today they went as a team, put Tottenham under pressure and didn't let them play. It was a perfect performance from them. They were the better team.
Ozil has been criticised for not tracking back. Not today. He was man of the match.
We keep hearing about the potential of Tottenham and their manager but to be classed as a good team they have to win a trophy soon.
Front three very good - Wenger
Tottenham manager Mauricio Pochettino told Sky Sports: "It was an even game in terms of shots on target, off target, possession. I am only disappointed because the effort was massive from the team.
"It is obvious you saw what happened in the game and the small details were against us, it makes it difficult to win. I am very proud with the effort."
Arsenal boss Arsene Wenger speaking to Match of the Day: "I am very proud of the performance of my team. We played with purpose, desire and urgency and looked dangerous with a great solidarity.
"Mustafi was outstanding, the back three were outstanding. We threw our bodies in front of shots and were good on crosses. It was a terrific performance from Ozil - he has shown he is not only a great football player but can work and play for the team. He worked hard defensively.
"All the front three were very good. It is difficult to single one individual out.
"We are very tight in the table. People want always to go quickly to different conclusions. Let us take the positives and transfer it to the next one."
Arsenal travel to Cologne in the Europa League on Thursday (kick-off 18:00 GMT), while Tottenham face Borussia Dortmund in the Champions League on Wednesday (19:45).
Ozil on the mark - the stats
- Arsenal have won 11 home Premier League games in a row, their best run since winning 13 consecutively at Highbury between February and November 2005.
- Pochettino has lost four of his past six London derbies as Spurs boss, as many as he had lost in his previous 18.
- Spurs have now lost three of their opening 12 Premier League games, only one fewer than in the whole of last season.
- Lacazette has been involved in five goals in his first six Premier League games at the Emirates (four goals, one assist).
- Lloris has never kept an away Premier League clean sheet against the 'big six', conceding 56 goals in 24 matches at an average of 2.3 per game.
- Gunners forward Sanchez ended a run of 11 league matches without scoring against the 'big six' - his previous goal came against Chelsea in September 2016.
- Since his Premier League debut in September 2013, Ozil has provided 45 assists, more than any other player in the competition and 21 more than any other Arsenal player in that time.
- All three of Mustafi's Premier League goals have been assisted by Ozil.
- Kane has failed to score in seven of his past nine London derbies in the Premier League - however, he had found the net in his previous five against the Gunners.
- 20MustafiBooked at 48mins
- 18MonrealBooked at 73mins
- 29XhakaBooked at 32mins
- 11ÖzilSubstituted forIwobiat 84'minutes
- 7SánchezBooked at 38mins
- 9LacazetteSubstituted forCoquelinat 73'minutes
- 6D Sánchez
- 19DembéléSubstituted forWinksat 62'minutes
- 10KaneBooked at 50minsSubstituted forLlorenteat 75'minutes
- 20AlliSubstituted forSon Heung-Minat 75'minutes
- 7Son Heung-Min
- Mike Dean
- Shots on Target
Second Half ends, Arsenal 2, Tottenham Hotspur 0.
Attempt missed. Davinson Sánchez (Tottenham Hotspur) header from the centre of the box misses to the left. Assisted by Christian Eriksen with a cross following a corner.
Corner, Tottenham Hotspur. Conceded by Granit Xhaka.
Attempt blocked. Son Heung-Min (Tottenham Hotspur) left footed shot from the centre of the box is blocked.
Attempt missed. Alex Iwobi (Arsenal) right footed shot from outside the box is close, but misses to the left. Assisted by Alexis Sánchez.
Attempt saved. Alexis Sánchez (Arsenal) right footed shot from the centre of the box is saved in the centre of the goal. Assisted by Francis Coquelin.
Attempt missed. Granit Xhaka (Arsenal) left footed shot from outside the box misses to the right from a direct free kick.
Foul by Jan Vertonghen (Tottenham Hotspur).
Alexis Sánchez (Arsenal) wins a free kick in the attacking half.
Attempt blocked. Alexis Sánchez (Arsenal) right footed shot from outside the box is blocked.
Foul by Ben Davies (Tottenham Hotspur).
Francis Coquelin (Arsenal) wins a free kick in the defensive half.
Attempt blocked. Sead Kolasinac (Arsenal) left footed shot from the left side of the box is blocked. Assisted by Alex Iwobi.
Attempt blocked. Alex Iwobi (Arsenal) right footed shot from the centre of the box is blocked. Assisted by Alexis Sánchez.
Attempt missed. Son Heung-Min (Tottenham Hotspur) right footed shot from the centre of the box is high and wide to the right. Assisted by Fernando Llorente with a headed pass.
Substitution, Arsenal. Alex Iwobi replaces Mesut Özil.
Attempt blocked. Héctor Bellerín (Arsenal) right footed shot from the right side of the box is blocked. Assisted by Mesut Özil.
Corner, Tottenham Hotspur. Conceded by Laurent Koscielny.
Attempt saved. Eric Dier (Tottenham Hotspur) header from the right side of the six yard box is saved in the centre of the goal. Assisted by Ben Davies with a cross.