Arsenal came out on top in the north London derby sinking rivals Tottenham in a scintillating match at the Emirates and leapfrogging them to go fourth in the Premier League table.
A brace from Gabonese striker Pierre-Emerick Aubameyang and strikes from Alexandre Lacazette and Lucas Torreira helped overhaul goals from Eric Dier and Harry Kane, who notched his eighth in eight derbies.
Aubameyang gave the home side the lead from the penalty spot in the 10th minute after a clumsy handball by Spurs' Jan Vertonghen, who flung his arm up to knock a corner kick off course and prevent Shkodran Mustafi from heading the ball goalward.
Tottenham flipped the match on its head within the half with goals from Eric Dier and Harry Kane, Dier heading in from a Christian Eriksen free kick and Kane scoring from the spot after Son Heung-min was judged to have been brought down in the area.
Aubameyang levelled again in the 56th minute before second-half substitute Lacazette put Arsenal ahead with a deflected strike from outside the area.
Torreira gave Arsenal a two-goal cushion minutes later, collecting a pass from Aubameyang, running forward unmarked and firing into the far corner past Hugo Lloris.
Arsenal, unbeaten in 19 games in all competitions, moved above Spurs into fourth place in the league on goal difference, with both teams on 30 points.
Arsenal have made a habit of saving their best for the second half this season, and Aubameyang said they had stayed confident despite trailing at half-time.
"After the first goal we conceded we had a moment where we were a bit down, but at half-time we were confident," he said on Sky Sports Premier League.
"We spoke, we knew that we can do it in the second half. With the fans, the atmosphere we felt strong and could go for the win.
"I think we can see always in the second half we played very well, we don't give up. That's the mentality."
The win lifts Arsenal above Tottenham into fourth in the table, but Aubameyang said that was not the main concern.
"The most important thing is the present right now," he said.
"We are looking of course to continue this series, we are still winning games and we're on an unbeaten run so we have to keep going."
AS IT HAPPENED: ARSENAL 4-2 TOTTENHAM
Arsenal boss Unai Emery said his players had fed off the support from their fans.
"I think we played with our support, there was a big atmosphere, they pushed a lot for us," he said on Sky Sports News.
"There were difficult moments in the first half but I think we kept calm. We spoke in the dressing room. We were having good minutes in the game but after the first half the result is not good.
"But we could continue with our work in the game and get the chances, the supporters are going to push us and in the second half we could win."
Opposite number Mauricio Pochettino called the result disappointing, and said Arsenal benefited from being able to rest players for their Europa League match in midweek.
"It was a very competitive game, very tough for us because of the fixtures," he said. "We were talking before about it being after Chelsea and Inter (Milan), so it's difficult.
"I think Arsenal competed with a lot of energy but the game was even until 2-2 in the second half. When we conceded the third goal it was tough for the team to come back and make the effort again.
"When we conceded the fourth and then of course with the sending off the game was over."
