Arsenal manager Arsene Wenger said his side's intensity had been the decisive factor in their 2-0 victory over north London derby rivals Tottenham Hotspur on Saturday.
Quick-fire first-half goals from Shkodran Mustafi and Alexis Sanchez at a drizzly Emirates Stadium earned Arsenal a first win over Tottenham since March 2014.
It was Arsenal's 11th successive home victory in league football and left them a point behind Spurs, who finished above them last season for the first time since 1995.
"They had the urgency, the desire and the focus," Wenger said.
"In a derby like that, that plays a part. We didn't lose the defensive focus for 90 minutes."
Wenger also hailed the display of German playmaker Mesut Ozil, who departed to a standing ovation late in the second half after an uncharacteristically battling performance.
"I'm convinced that Mesut Ozil adds physicality to his game and when he needs it, he can produce it," the Frenchman told Sky Sports.
"He got a standing ovation because he added to the team's defensive job. He's not a specialist in that, but he can do that because he's an intelligent man."
Spurs manager Mauricio Pochettino was unhappy about the free-kick that led to Mustafi's 36th-minute opener, which was awarded for a challenge on Sanchez by Davinson Sanchez that looked clean.
Mustafi was also narrowly offside as Ozil struck his free-kick and Arsenal profited from the benefit of the doubt in a possible offside call against Alexandre Lacazette prior to Sanchez's goal.
"You saw what happened during the game," Pochettino said.
"I'm disappointed because the small details were against us, which makes it difficult to win."
Asked about which "small details" he was referring to, Pochettino replied: "The free-kick. And I think it was offside.
"In this type of game, when you play against a top-six side like Arsenal, the small details change games and put the game on one side."
Wenger said: "I don't see where the referee's decisions went for us. For me, the foul (by Sanchez on Sanchez) was a foul.
"I can give you plenty of games since the start of the season when we had bad luck."