By Chris Harris
Mohamed Elneny smashed in a goal of the season contender as we completed a flawless Europa League group stage.
Our Egypt midfielder found the top corner from 25 yards to double our lead after Eddie Nketiah's early opener.
Jordan Flores pulled one back for Dundalk but we always looked in control, and Joe Willock rammed in a third goal to put the result beyond doubt.
Folarin Balogun's cool finish made it four before Sean Hoare headed a late consolation.
Mikel Arteta changed his entire starting line-up and we began brightly, pressing high up on a less-than-ideal surface.
Nketiah's energy set the tone and he got his reward when he closed down Andy Boyle and blocked his clearance before nonchalantly lifting the ball over Gary Rogers.
The Dundalk goalkeeper had even less chance six minutes later when Elneny took aim from left of centre, around 25 yards out. His fierce shot arrowed beyond Rogers and into the far top corner.
Dundalk had barely registered an attack but Flores got forward to play a neat one-two and fire powerfully beyond Alex Runarsson.
The home side rallied and we needed a last-ditch block from Calum Chambers - making his first start for almost a year - to protect our lead.
Ainsley Maitland-Niles and Cedric both tested Rogers from range and the latter forced another save with a free-kick from the edge of the box.
Then Balogun got another chance to shine as a substitute - and he took it.
First he held the ball up impressively and found Willock for a shimmy and a low shot that found its way underneath Rogers.
Balogun rounded off a comfortable win with a calm finish into the bottom corner after good work from Pepe, and Hoare's late header was no more than a footnote.
HOW IT HAPPENED
WHAT IT MEANS
Ben Cottrell and Miguel Azeez are the 877th and 878th players to represent our men's team
We've recorded a sixth consecutive win in European competition for the first time since November 2005
We're unbeaten in nine away games in Europe, our longest run since March 1995
We're the only team left in European competition with a 100 per cent win rate this season
Before kick-off a minute's silence was observed to mark the death of Italy legend Paolo Rossi at the age of 64
Arteta made wholesale changes for our final Europa League group game and our first competitive game in Ireland.
Perhaps the standout name on the teamsheet was Chambers - this was his first start for 347 days following his recovery from a long-term injury.
A clash of heads in training ruled out Reiss Nelson, and Sead Kolasinac also played no part.
Pablo Mari and Emile Smith Rowe both started, Shkodran Mustafi was named as captain, and Nketiah lead the line with Balogun among the substitutes.
We've now got back-to-back home games in the Premier League.
Burnley visit Emirates Stadium on Sunday and Southampton are our visitors next Wednesday.
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