Mikel Arteta said Eberechi Eze's brilliant hat-trick in Arsenal's 4-1 demolition of Tottenham on Sunday was just reward for the midfielder's "exceptional" commitment to improve.
Eze became only the fourth player to score a north London derby treble and the first to hit three in the bitter rivalry since Alan Sunderland in 1978.
The 27-year-old midfielder tore Tottenham to shreds with clinical finishes in the 41st, 46th and 76th minutes at the Emirates Stadium.
Leandro Trossard netted in the 36th minute to open the floodgates before Eze stole the show with the first treble of his professional career.
Richarlison's incredible 35-yard chip over Gunners keeper David Raya in the 55th minute was no consolation for toothless Tottenham.
While Eze had made a relatively slow start to his Arsenal career since his £60 million ($78 million) move from Crystal Palace in August, Arteta has been impressed with the England star's dedication.
That desire to improve was on show when he reported back early from the recent international break.
"I'm so happy for him. It is a day he deserves. At any minute he can win us a game," Arteta said.
"Things happen for a reason. After the international duty he had two days off, but after one day he went to training. Because he wants to improve. He was asking me questions.
"He can score from the right, the left, in the ground, with the ball bouncing, he has such a capacity to take these chances. He is exceptional. We need to play to his qualities."
Eze had snubbed Tottenham's interest in favour of joining Arsenal and his eye-catching performance underlined just what their rivals missed out on.
"When I picked up the phone to him in the summer I remember he said he wanted to play for us and be part of this team. You can really sense that. Hopefully he enjoys this day," Arteta said.
It was a memorable afternoon for Arsenal, whose biggest win over Tottenham since 2012 extended their lead at the top of the Premier League to six points.
SUPER DOMINANT ARSENAL
"A great day. We enjoyed every minute of it. Since the players came back from international duty I sensed they were ready for a big week. Their preparation was top," Arteta said.
"It is the application, the energy and the desire to win. It is without a question the biggest attribute for this team.
"We were exceptional from minute one. We were super dominant. A day to remember. You don't always win a derby 4-1."
With champions Liverpool in turmoil and Manchester City also spluttering after Saturday's loss at Newcastle, Arteta's side are in pole position in the title race.
After three successive runners-up finishes in the Premier League, this season is a golden opportunity to finally end their wait for a first title since 2004.
Although Arsenal are unbeaten in 15 matches in all competitions, Arteta refused to get carried away ahead of a big week featuring a Champions League visit from Bayern Munich and a trip to second-placed Chelsea in the Premier League next weekend.
Asked how much confidence he took from the manner Arsenal's victory, Arteta said: "In this league? Not much. It means we are doing well and winning games."
Tottenham boss Thomas Frank was forced to apologise after his first taste of the north London derby raised fresh questions about his cautious tactics.
"Where do I start? It was hugely disappointing that we don't perform better against our biggest rival. I can only apologise to the fans for that," he said.
Frank had already been criticised for his pragmatic game plans and Tottenham's latest tepid display forced him to defend his philosophy.
"Very emotional and frustrated right now. I take full responsibility. But what I will say is we needed to be more aggressive no matter the system," he said.
"I'm a big believer that no matter what system you play you can be successful.
"We didn't win enough of those duels, whether that was a lack of fight or whatever it is."