Joel Matip opened the scoring with a header off a corner just before the break, while Mohamed Salah benefitted from a pair of David Luiz mistakes to score a second-half brace. Lucas Torreira netted a late consolation goal for the visitors.
Both teams entered Saturday's showpiece as the only remaining clubs in the Premier League with an unblemished record.
Arsenal seemingly struggled to get out of their own half for large portions of the opening 45 minutes, but a pair of chances gave fans hope of coming away with a positive result.
Pierre-Emerick Aubameyang looked as though he would open the scoring off of Adrian's poor clearance, but the Gabon forward's lob narrowly missed a wide-open net as the Spanish 'keeper scrambled back to his line.
Arsenal's club-record signing Nicolas Pepe also came close when his curling strike missed the top corner by inches.
Then, three minutes after the break, Luiz brought Salah down in the box before the Egyptian calmly converted to double Liverpool's lead. He made it 3-0 at Luiz's expense shortly after with a fine run and finish to put the match out of reach for the visitors.
Along with strengthening Anfield's reputation as a fortress, Liverpool also managed to win their 12th Premier League match in a row - their best-ever run in the competition.
Arsenal will attempt to rebound next week during the season's first north London derby against Tottenham at the Emirates Stadium, while Liverpool takes on Burnley in their bid to remain perfect.