Arsenal came from behind to beat Tottenham 5-2 in the Premier League, seizing control of the north London derby after its former striker Emmanuel Adebayor was sent off having scored the opener.
Adebayor netted his first league goal of the season in the 10th minute but was dismissed eight minutes later for a dangerous high challenge on Santi Cazorla.
Per Mertesacker started Arsenal's comeback with a 24th-minute header, and Lukas Podolski and Olivier Giroud both found the net before halftime.
Cazorla swept in the fourth goal on the hour before Gareth Bale reduced the deficit for Tottenham, and Theo Walcott knocked in the fifth in stoppage time.
By replicating its 5-2 derby win in February, Arsenal rose above Tottenham in the standings to sixth after the club's worst start to a season since Arsene Wenger took charge in 1996.
''If we show that courage and ambition every game we will climb up the table,'' Walcott said.
''We showed people how good we are today ... it will give us tremendous spirit.''
Tottenham started with two former Arsenal players and both William Gallas and Adebayor found the net first. Gallas' goal was ruled out for offside but a minute later there was no disputing Adebayor's effort.
Jermain Defoe latched onto Jan Vertonghen's deep ball, cut in from the right and his shot was parried by Wojciech Szczesny, who was returning from a two-month layoff.
But Adebayor was on hand to nudge the loose ball over the line against the club he left in 2009. With their lead, Spurs upped the pressure and Aaron Lennon came close to doubling the advantage, but his shot crept round the post.
And the match swung in Arsenal's favor when Adebayor launched his high challenge at Cazorla, hitting the midfielder's right ankle and completely missing the ball.
Referee Howard Webb showed Adebayor a straight red card on just his second start of the league season and, as tensions increased, Arsenal midfielder Jack Wilshere and Bale were also involved in an altercation.
With its numerical advantage, Arsenal drew level in the 24th minute as Walcott went past Kyle Naughton and whipped in the cross that Mertesacker met with a powerful header.
Arsenal was now in in command, with a couple of dangerous headers coming from Giroud, although acrobatic goalkeeper Hugo Lloris did well to block them both after he dislodged Brad Friedel from a Tottenham league lineup for the first time since October 7.
Arsenal, though, went in front in the 42nd when Wilshere slotted the ball through to Podolski and the Germany striker's scuffed shot deflected off Gallas into the net.
And in first-half stoppage time, Cazorla stayed on his feet after being fouled, regained his composure and went out to the left. From there, he crossed to Giroud, who swept the ball into the net.
Trailing 3-1, Tottenham manager Andre Villa-Boas at half time took off two of the back four, Naughton and Kyle Walker, and brought on defender Michael Dawson and striker Clint Dempsey.
It didn't make much of a difference, although Cazorla took until the hour-mark to score Arsenal's fourth.
The Spaniard netted at the far post after connecting with Podolski's cross.
But Arsenal switched off at the back, allowing Bale to rampage through before knocking the ball past Szczesny with his weaker right foot to give Spurs a brief hope of a comeback. It wasn't to be.
The three-goal cushion was restored in stoppage time when Alex Oxlade-Chamberlain charged down the right and crossed to Walcott, who controlled the ball before striking past Lloris.