First-half goals from Kai Havertz and Bukayo Saka set the Gunners on their way before captain Martin Odegaard sealed victory just after the break.
Mikel Arteta hailed the spirit of his squad at full-time and the Spanish boss has been busy in the transfer market once again this summer.
The club agreed a £51M deal for Ezri Konsa just hours before kickoff on the back of previous swoops for Bruno Guimaraes and Christos Tzolis after the 2026 FIFA World Cup.
Despite Havertz opening the scoring, there are still doubts over his ability - and that of Viktor Gyokeres - to go over 20 goals in the Premier League - and Arteta is rumoured to be planning a sensational bid for Atletico Madrid's Julian Alvarez.
Time is against Arteta - and Alvarez reportedly only wants to join Barcelona if he leaves Atletico - but former Premier League winner Gary Neville claimed Arsenal need a star striker to turbo power their title push in 2026/27.
"What a squad Arteta has built. If he puts another forward into that, if they could get Julian Alvarez somehow, that'd light this place up as you'd have a world class striker to go with all the world class defenders and midfielders.
"They wouldn't just become Premier League title winners they'd go the next step and win a Champions League. It's a massive 10 days. He needs a bit of magic up front - someone that can win a game for you when you don't play well."