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.
After losing his first two matches - to champions Manchester City and Chelsea - the new boss has overseen a run of nine wins in a row in all competitions.
Arsenal started the second half on the front foot and after Hector Bellerin had gone close we found the second goal as Lacazette fired home a superb effort from 20 yards in the 48th minute.
Liverpool, who remain unbeaten in their last 18 home games against City, came out roaring and dominated the opening 10 minutes but Pep Guardiola's visiting side weathered that early storm and were the more unsafe after the break.
Slavisa Jokanovic has admitted that Fulham can not compete in the Premier League if their dismal defending continues. We're not afraid to play anyone. Waiting until the end of the season to have him for free is a gamble any club will not want to take.
"Then Aaron is like a 10 player, but he can play near the attack and he can score or do an assist like today". Arsenal has now 18 points from 8 games while Chelsea still has the chance to reclaim the lost spot when they face Southampton.
The Germany worldwide split the two Arsenal centre-backs and his deft lob from Vietto's slide-rule pass deservedly saw Fulham draw level just before the interval.
"The most important thing here is not that Torreira is the best player on the pitch, or that any other is the best, but what matters is that we win and keep growing as a team", Torreira said. We will continue with this victory'. I think we are in the first part of the war.
To make matters worse for Fulham, as the clock headed into stoppage time, Ramsey played Aubameyang in behind the defence and the former Borussia Dortmund star took the ball into the box before drilling it across the keeper and into the bottom corner to put the cherry on top of the cake.