Liverpool ended Arsenal's 10-game unbeaten run in all competitions with a devastatingly routine victory at Anfield.
Sadio Mane grabbed the opener when he headed in Trent Alexander-Arnold's free-kick in the first half.
Diogo Jota took advantage of a Nuno Tavares mistake to roll into an empty net before Mohamed Salah slotted home a Mane cross for the third.
Right-back Alexander-Arnold was the provider again when he teed up Japanese substitute Takumi Minamino to make it 4-0 with his first touch, just 48 seconds after coming on.
Victory for Liverpool sees them jump up to second in the Premier League, while Arsenal remain in fifth.