A first half to forget cost Everton dear as the Blues suffered defeat at Emirates Stadium on Saturday.
The Toffees hadn’t won at the home of the Gunners since 1996 - and that sequence was extended on a chilly evening in the capital.
Dominic Calvert-Lewin scored two minutes after stepping off the bench, but by that time Everton already trailed to Aaron Ramsey’s double and further strikes from Laurent Koscielny and debutant Pierre-Emerick Aubameyang.
Ramsey then completed his hat-trick with a quarter of an hour remaining to consign Sam Allardyce’s side to a disappointing reverse.
Three days and two training sessions after switching from Manchester City, Eliaquim Mangala was handed his Everton debut in a reshuffled three-at-the-back formation.
Ashley Williams returned as captain, as did Yannick Bolasie, Morgan Schneiderlin and Jonjoe Kenny, who took the place of Seamus Coleman on the right-side of defence.
The Irishman, on the back of his outstanding comeback performance in the midweek win over Leicester City, did not travel to the capital.
A speedy forward line of Theo Walcott, Bolasie and Oumar Niasse was selected to offer a threat on the break.
Arsenal had lost 3-1 at Swansea City last time out but their home form had been impressive, with eight league wins already in north London during 2017/18.
And it didn’t take long for the hosts to hit their stride, Ramsey, unmarked, sweeping home inside the six-yard box after Mesut Ozil and home debutant Henrikh Mkhitaryan had combined.
Having been provider, the Armenian was only an inch away from scoring in Arsenal’s next attack. His crisp shot from 25 yards skimmed the outside of the post, with Jordan Pickford at full stretch.
After deadline-day recruit Aubameyang saw a predatory goal-bound effort deflected wide, the Gunners bagged a second early goal. From the resulting corner, centre-back Shkodran Mustafi nodded towards the far post, where fellow defender Koscielny pounced from a matter of yards.
Nineteen minutes in and the margin became three goals as Ramsey hit a first-time drive from distance, with the ball cruelly flicking off Mangala and Williams, wrong-footing Pickford and finding the target, despite the England keeper’s best attempts to keep it out.
Everton’s efforts to haul themselves back into the contest first came via the boot of Cuco Martina, but the full-back’s volley from the edge of the penalty box was sliced wide.
Minutes later only an outstanding piece of defensive play from Mustafi prevented Walcott - a scorer of over 100 goals in Arsenal colours - from netting on his return to the Emirates.
The winger latched on to Niasse’s splitting pass and strode forward, only to see Mustafi slide in and divert his shot up and over the bar. Without a touch from the German, Walcott would have no doubt netted.
However, Arsenal ensured they held a four-goal lead at the interval when Aubameyang clipped over Pickford, moments after the Blues goalkeeper had stood up to push away the former Dortmund striker’s run-and-shot. It should have been disallowed for offside but the assistant referee didn’t flag and the goal wrongly stood.
Allardyce took off Keane and brought on Tom Davies at the restart, also altering the defensive formation to a flat back-four.
It was a much better start, too - Walcott was unlucky that his fizzing volley struck Hector Bellerin, and the same Everton player then delivered a delicious cross from the right which was prodded against the frame by Niasse. The Senegal striker did all that he could on the stretch and was frustratingly denied by the post.
Walcott’s evening was brought to an end on the hour mark. Unsurprisingly, he received an excellent reception from the Arsenal fans when he was replaced by Calvert-Lewin, in recognition of the 12 years service he offered to the Gunners.
Two minutes after his introduction, Calvert-Lewin climbed to head a goal back for the Toffees. Davies passed to Martina and the full-back’s left-sided cross was powered in by the England Under-21 international - his eighth goal of the campaign in all competitions.
Hope of an Everton fightback was extinguished, however, when Ramsey wrapped up his hat-trick a quarter of an hour before the end, the Welshman taking advantage of another Mkhitaryan assist to slot the ball low past Pickford’s left hand and complete the scoring.