Molde arrived in north London as the defending Eliteserien champions after they romped to the title last year.
Erling Moe’s side will be hard pressed to repeat their domestic triumph this season as they trail Bodo/Glimt by a country mile, even if they beat them 4-2 last month.
Their high tempo possession based football has won plaudits for the intensity of their play in a 4-2-3-1 formation, with an emphasis on their overlapping full-backs supplementing attacks down the flank.
Moe’s side could have been playing in the Champions League group stages after they narrowly lost out to Ferencvaros on away goals.
Moe replaced Manchester United bound Ole Gunnar Solskjaer, firstly as caretaker boss, when he left for Old Trafford in December 2018. Moe, a former Molde player, had been Solskjaer's assistant and was handed the role on a permanent basis when it became clear Solskjaer would not return.
David Luiz returned to Mikel Arteta’s starting XI as the Arsenal manager made changes with Eddie Nketiah also in the line-up while Pierre-Emerick Aubameyang moved to the bench after his winning penalty against the Red Devils, as his boss eyed the league fixture against Aston Villa on Sunday.
Two other heroes from the weekend, Mohammed Elneny and Thomas Partey were also given a night off and sat on the bench on a chilly night at the Emirates.
The Gunners would be aiming to target Henry Wingo - a young but raw talent slotted into the side following an injury to Kristoffer Haraldseid, who tore an ACL shortly before the start of the new season.
Molde would be pleased defender Martin Bjornbak was in the side, back in the team after missing the whole of August, while another in their backline, Stian Gregarsen, had also just returned after a lengthy spell on the sidelines.
While Molde started the match a whopping 16 points behind Norway league leaders Bodo/Glimnt, they were equal top with the Gunners in Group B on Thursday evening.
Both sides had won their opening pair of games, Arsenal emerging from their trip to Rapid Vienna last month with a 2-1 victory, supplemented with a 3-0 win over Dundalk last time out at the Emirates.
Molde came into the clash buoyed by a 2-1 triumph over Dundalk and by defeating Rapid 2-1 in Scandinavia.
Statistics were against Molde with no side from Norway beating an English side in this country, even if it the fixture on Bonfire Night was Erling’s side’s first fixture against a side from the Premier League.
Arsenal’s last match against opponents from Norway saw Arsene Wenger’s side run out 5-1 victors against Rosenborg in December 2004 at Highbury. Goals that night came from with goals from José Antonio Reyes, Thierry Henry, Cesc Fàbregas, Robert Pires and Robin van Persie.
Fireworks filled the north London air but would there be any on the pitch?
The home side started well, with Eddie Nketiah looking lively for Arsenal early on, forcing a good save from Molde keeper Andreas Linde after only five minutes.
Yet Molde were well-organised and disciplined, proving a stubborn opponent to break down in a largely shapeless opening 20 minutes as both sides probed each others weaknesses without landing too many blows.
That was to change on 22 minute when Bernd Leno’s clearance was won by back an eager Molde side who worked the ball to Martin Ellingsen on the right hand side of the box via Magnus Wolff Eikrem.
Ellingsen, a 25-year-old midfielder, took no time in teeing up an outstanding left-footed curler low past Leno’s right-hand and into the net to make it 1-0 to Molde – much to the joy of their playing staff and squad at the Emirates.
Despite an occasional ball into Molde’s box, normally met by an unconvincing header from the home side Arsenal looked uninspired against the resolute visitors.
The Scandinavians could have even doubled their lead but for a fine save from Leno, low to his near post from Ohi Omoijuanfo.
Henry Wingo was then denied with a right-footed shot shortly afterwards and just as Arteta’s side looked to be heading into the break a goal down the Gunners broke before Joe Willock hounded Kristoffer Haugen into forcing the ball into his own net to make it 1-1 moments before half time.
The equaliser was somewhat fortuitous, but no-one in red and white was complaining.
Sead Kolasinac could have put the Gunners ahead on 53 minutes but he swept the ball over the ball when well placed.
The pressure eventually told as Arsenal went ahead on 62 minutes when Granit Xhaka played a ball over the top to Willock who squared to force a second own goal from the visitors, this time through Sheriff Sinyan as Arteta’s side went 2-1 ahead.
Moments later Kolasinac crossed deep for Pepe to force to save from shotstopper Linde.
After a spell of concerted pressure the home side made it 3-1 on 69 minutes, through an excellent Pepe left-footed shot, after substitute Bukayo Saka – on for the disappointing Willian – found the £72m man just inside the box.
As the clock ticked down Saka received a yellow for an agricultural challenge, while Mohammed Elneny replaced Dani Ceballos and Kieran Tierney came on for Xhaka.
The home side sealed an emphatic win when Willock fired home with moments remaining as referee David Borbalan blew to end the match soon afterwards.
While Willock’s goal was fully deserved for his enthusiastic endeavours throughout the game, the emphatic 4-1 scoreline was slightly harsh on Molde.
Man of the match - Joe Willock
Pepe’s goal was excellent, as was Saka’s contribution for the strike, but the award had to go to Willock for his all-action display - which not only saw him grab a late goal, but also earn his side an own goal after harrying the Molde backline. Something he did for the whole 90 minutes.