Jose Mourinho's Chelsea restored order with a battling 2-0 win over nine-man Arsenal at Stamford Bridge.
The champions won at home for the first time in the Barclays Premier League this season as Kurt Zouma headed in and Eden Hazard's late shot ricocheted in off Calum Chambers.
The Blues, now unbeaten in eight league games with the Gunners, benefited from Arsenal indiscipline as Gabriel was sent off after a series of altercations with Diego Costa and Santi Cazorla followed for two bookable offences.
Chelsea striker Costa might have seen red himself after catching Laurent Koscielny with a flailing arm and chest-butting the Frenchman.
When Gabriel intervened, he became the subject of Costa's attention and the Gunners defender naively retaliated.
After both men were booked by referee Mike Dean, Gabriel kicked Costa and was shown a straight red card.
Mourinho would argue the Brazilian should have conceded a penalty by then after earlier grappling with Hazard.
It mattered not as Arsene Wenger suffered the familiar feeling of defeat to Mourinho's Chelsea.
The bitter rivals shook hands in the moments before kick-off in a temporary truce to their feud.
Wenger recorded a first win over his bitter rival at the 14th attempt in August's Community Shield, but evaded the Portuguese post-match.
Mourinho had been in position to congratulate his rival and he offered his hand this time and it was accepted.
Both sides had plenty to prove; Chelsea that talk of a crisis was wrong and Arsenal that they can contend for the title.
After five rounds of matches, no team had conceded more than Chelsea's 12 goals and, fearful of Arsenal's pace, Mourinho left out captain John Terry again.
The pace was furious, but accuracy was lacking and so were opportunities.
Arsenal would not be cowed by Chelsea and the soft underbelly of recent seasons was not in evidence.
Costa was lively and saw one drive held by Petr Cech, who returned to Stamford Bridge as an Arsenal player following 11 years' distinguished service as a Blue.
Theo Walcott, again chosen to lead the line, saw a tame effort held by Asmir Begovic and next Cech smothered as Pedro tried to control a Cesc Fabregas pass over the top.
Zouma recovered from a slip to block Walcott as he threatened to go through one on one and Aaron Ramsey hesitated when he had a chance to finish an Arsenal counter.
Chelsea's control on the game grew and Cech punched away a Pedro drive before Costa and Koscielny grappled, with the striker pushing the defender in the face and flinging out his arm.
He went to ground and next barged the Frenchman with his chest on standing up.
Gabriel became involved, needlessly, and saw red.
Zouma headed in Fabregas' set-piece at the back post to give Chelsea the lead and Hazard stung the hands of Cech soon after.
Alexis Sanchez scuffed a half-chance after Chelsea allowed the ball to bounce in the area.
Walcott fired over and Hazard shot wide across goal when Chelsea responded.
Costa wanted a spot-kick for tussle with Hector Bellerin before Arsenal's numerical disadvantage was doubled when Cazorla received a second yellow card for tripping Fabregas.
Cech could do nothing about Hazard's shot, which deflected wickedly off Chambers for Chelsea's second.
TWEET OF THE MATCH
Gary Lineker @GaryLineker
Can't imagine what Costa would be like with a few drinks inside him.
Asmir Begovic: 6 (out of 10)
Branislav Ivanovic: 6
Cesar Azpilicueta: 7
Kurt Zouma: 7
Gary Cahill: 7
Nemanja Matic: 6
Cesc Fabregas: 6
Diego Costa: 6
Eden Hazard: 6
Loic Remy: 6
John Obi Mikel: 6
Petr Cech: 7
Hector Bellerin: 6
Nacho Monreal: 6
Laurent Koscielny: 6
Francis Coquelin: 6
Aaron Ramsey: 6
Santi Cazorla: 6
Theo Walcott: 6
Alexis Sanchez: 6
Mesut Ozil: 6
Calum Chambers: 6
Alex Oxlade-Chamberlain: 6
Olivier Giroud: 6
Oscar. The Brazil playmaker was everywhere in attack and defence. His work-rate is what Jose Mourinho demands of all of his players and he was only taken off after being shown a yellow card.
MOMENT OF THE MATCH
Feuding Brazilians Diego Costa, who is Brazil-born but represents Spain, and Gabriel had a running squabble. Naively the Arsenal defender responded to Costa's taunts and did his team a great disservice in getting sent off.
VIEW FROM THE BENCH
Chelsea captain John Terry was again left out of the starting XI and it was a decision which was vindicated by the performances of Gary Cahill and Kurt Zouma. Branislav Ivanovic also justified his selection with a return to more reliable times. Theo Walcott was again chosen to lead Arsenal's attack, but had little support. Arsene Wenger had few options once Gabriel was dismissed.
MOAN OF THE MATCH
Costa relishes niggle, but he did little else against Arsenal. The striker was prolific in the first few weeks of his first season last term, but has flattered to deceive in front of goal. He needs to offer more than as a playground bully.
WHO'S UP NEXT
Walsall v Chelsea (Capital One Cup, Wednesday, September 23)
Tottenham v Arsenal (Capital One Cup, Wednesday, September 23)