Alexander-Arnold, Mohamed Salah, Fabinho and Sadio Mane were all on target for the Reds.
Following a fairly one-sided opening half of football, Liverpool took a two-goal lead before the first half break.
The Reds were in total control for much of the first half and, after a handful of missed opportunities, Alexander-Arnold broke the deadlock after 23 minutes with a pinpoint free-kick.
Henderson then hit the post two minutes later, before Salah doubled the hosts’ lead on the brink of half time.
55 minutes on the clock, Robertson slides the ball to his right for Fabinho, who unleashed a pinpoint long-range strike from distance that sailed beyond Hennessey and into the bottom right corner to make it 3-0 for the host.
14 minutes on, Salah picks the ball up on the halfway line and plays a first-time pass beyond the Palace defence for Mane to chase.
The winger latched onto the loose ball, sets himself, and steers his shot into the bottom right corner following a quick counter.
A one-sided contest, should City claim victory over Frank Lampard’s Chelsea tomorrow, then the Reds can secure the title in their upcoming fixture when they travel to Etihad Stadium to face Guardiola’s side.
While Palace will be seeking to bounce back when they host Burnley next time out in the league.