Gabriel rectified a dreadful error by scoring the winner in a 2-1 victory at home to Fulham on Saturday as Arsenal won their fourth straight game to start the Premier League season.
Aleksandar Mitrovic punished a mistake by Gabriel to give Fulham a surprise lead on 56 minutes, but Martin Odegaard equalised with a deflected effort just past the hour.
Gabriel bundled in after a scramble at a corner with five minutes to play to keep Mikel Arteta's side two points clear of reigning champions Manchester City at the top.
Fulham suffered their first defeat in four outings on their top-flight return.
Arteta believes Arsenal have "grown up" and "matured" after Gabriel gave his side a comeback victory.
In the last Premier League campaign, Arsenal only came from behind once to win, but showed composure against Fulham, earning the praise of Arteta.
"We've grown up, we have more alternatives, I think we have matured as well," the Arsenal boss said.
"Playing in front of these supporters helps because they are driving you as well and then it's about belief.
"A lot of that is about belief and confidence that you can do it and now we have that."
Arteta insisted Gabriel wants to reach his full potential after he made amends for his costly mistake for Fulham's opener.
When asked what has changed in terms of the defender's mentality, Arteta said: "How he looks after himself every day, what is most important in his life apart from his little daughter and his family and how consistent he is every day in his habits and how much he really wants to become one of the best."
Earlier, Arteta said Arsenal could sign a replacement for Nicolas Pepe after the Ivory Coast winger left the Premier League leaders to join Nice.
Pepe's loan move to Ligue 1 has increased the chances of Arsenal making another move into the transfer market before the summer window closes on September 1.
Arsenal have been linked with a move for Wolves winger Pedro Neto and Arteta admitted he could adapt his transfer philosophy after prioritising early deals for Manchester City duo Gabriel Jesus and Oleksandr Zinchenko at the start of the window.
"We have done it in a different way. At the start of the window we signed players before getting other players out," Arteta said.
"Now we have done something different, we have let a player go and maybe we'll be able to recruit somebody.
"But it's not a guarantee because the players are still not here. What I guarantee is the day the window closes, for me this is the best team in the world and I will try to get the best out of them, that's it."