Unai Emergy's side were leading 2-1 when the Spanish coach turned to the Gabon worldwide and teammate Aaron Ramsey off the bench midway through the second half, with two goals from Alexandre Lacazette coming either side of Andre Schurrle's strike.
Pierre-Emerick Aubameyang netted twice off the bench after Ramsey had finished off a vintage Gunners move moments after his introduction as a substitute.
After the global break, Arsenal resume their Premier League campaign at come against Leicester City on October 22, before a Champions League clash away at Sporting Lisbon and a London derby with Crystal Palace.
Aaron Ramsey's audacious back-heeled goal put Arsenal in complete control to cap a stunning move that recalled the club's finest days under Emery's predecessor Arsene Wenger. We can get better from this performance.
'It is very hard but we must prepare, continue improving and show big commitment'.
Fulham boss Slavisa Jokanovic felt hard done by, especially after his side had gone in level at half-time after Schurrle lifted the ball over new Arsenal goalkeeper Bernd Leno. We need them to support us.
It was Arsenal who nearly regained the lead less than three minutes into the second half but Bettinelli pulled off a great save to deny Bellerin from the edge of the box. They are helping us with their quality'.
Keown admits he is surprised to see Danny Welbeck being handed his first Premier League start of the season and Henrikh Mkhitaryan make his first league start since August 25.
"I believe my team tried".
Asked about the playmaker's injury, Emery replied: 'Yesterday he came in with pain and he could not train or play today'. "We are going to continue working".
- Arsenal have a 51.5% win rate in Premier League London derbies (124/241) - the best in the division.