When Martin Odegaard was fouled inside the area by Ryan Christie, Bukayo Saka handed the spot-kick duty to Havertz, and the German was engulfed by his delighted team-mates after he slotted home from 12 yards.
"It will probably change everything," Arteta told the club's official website, "But first of all, if he had any question marks about how we feel about him, how much we love him, how much we appreciate everything that he does, I think that’s out.
"We have all tried to give him support and the right tools to do what he has to do. He’s doing so many great things in the game. It was about that moment, that was the question that had to be resolved, and today he’s done it.
"To show that level of empathy and understanding and worrying and caring for somebody, it’s just great.
"I am really happy for the win, but even happier to be part of something, part of a team that shows the human qualities that they have shown today."
Midfielder Declan Rice joined every other Arsenal outfield player in celebrating with Havertz, and spoke in glowing terms about his team-mate.
"It was emotional, for the fans, for Kai, for everyone involved, because we want him to succeed so much," said Rice.
“Honestly, he works his socks off every day in training. In games he gives absolutely everything.
💬 “It was emotional, for the fans, for Kai, for everyone involved, because we want him to succeed so much."— Arsenal (@Arsenal) September 30, 2023
🗞️ Declan Rice was full of praise for Kai Havertz after his first Arsenal goal 👇
"He’s had chances to score this year, hadn’t scored yet, but today to slot away a penalty in that high pressure moment, shows the mindset that he’s got, shows the talent he’s got and his all-round performance was so special, I’m so happy for him.”