Arsenal manager Arsene Wenger lauded Theo Walcott as a "completely different player" after the forward continued his impressive start to the season.
Walcott netted his third Premier League goal of the campaign as Wenger's men claimed a 3-0 win over Chelsea on Saturday.
The England international was hailed by his manager after Arsenal claimed a league win over their London rivals for the first time since October 2011.
"You cannot question his performance," Wenger told a news conference.
"But I believe more the change in Theo Walcott is his attitude to this season. He's ready to fight, commit and straight away he gets the crowd behind him.
"Theo Walcott of that stature is a completely different player."
Alexis Sanchez and Mesut Ozil were also on the scoresheet in a stunning first half at the Emirates Stadium.
After 20 years in charge of Arsenal, Wenger insists his desire is as high as ever.
"I'm hungrier because I know I don't have 20 years in front of me," the Frenchman said.
"Also I feel more responsibility, you're not 20 years somewhere and you don't care about things.
"I'm more conscious of what Arsenal is all about so I think the weight of keeping people happy and making people happy is heavier than when I arrived."