Eddie Nketiah and Folarin Balorun were on target again as Arsenal comfortably defeated Dundalk at the Aviva Stadium with Mikel Arteta's side concluding their Group B campaign with a 100 per cent winning record.
With top spot in the group assured before kick off, Arteta made 11 changes from the side that lost to Tottenham on Sunday, with Nketiah chosen to lead the line. And the 21-year-old opened the scoring with his fifth goal of the season - making him the club's top goalscorer - charging down Andy Doyle's clearance and dinking it over goalkeeper Gary Rogers.
Mohamed Elneny scored a screamer from 30 yards just minutes later as Arsenal chalked up a lead reflective of their dominance.
But Dundalk - playing their final match of the season, with the contracts of 14 players set to expire before the new term - halved the deficit through former Wigan Athletic player Jordan Flores, who beat Arsenal goalkeeper Runar Runarsson. And the League of Ireland side could have been level on the stroke of half-time only for an important block from Calum Chambers - making his first start in almost a year - to deny Patrick Leahy.
Arsenal toiled for much of the second half on a poor surface, but Joe Willock finally put the game to bed in the 67th minute, poking home after a fine assist from substitute Balogun, who scored his second of the competition and Arsenal's fourth on the night after being released by Nicolas Pepe, before Sean Hoare scored a late consolation for the hosts.
The victory means Arsenal progress to the knockout stages of the competition with six wins from six games, while Dundalk end their campaign without a point.
TALKING POINT - Nketiah and Balogun give Arteta more food for thought
The opposition has to be taken into account, of course, but Arteta said in his pre-match press conference that the youngsters and fringe players had an opportunity to stake their claim for a place in the first team, with Arsenal struggling domestically. It wasn't exactly a convincing team performance, and the poor pitch made life difficult, but Arsenal's forwards on the night certainly gives Arteta more food for thought.
Nketiah demonstrated his obvious qualities with his third goal of the competition, and it's telling that the 21-year-old is now the club's top goalscorer this season despite a lack of playing time. There has been uncertainty about Balogun's future, with the 19-year-old's contract up next year, but this was another impressive cameo. His approach play, strength, vision and eye for goal was clear to see. He looks a class act and Arsenal would do well to tie up his future as soon as possible.
Whether either player is good enough right now for a Premier League side with top six aspirations remains to be seen, but their performances in Europe so far this campaign have certainly done their chances for the future no harm.
MAN OF THE MATCH - Eddie Nketiah (Arsenal)
He was a real livewire leading Arsenal's attack, always making the run into space and giving team mates options, before he made way for Balogun just past the hour-mark.
Dundalk: Rogers 6, Hoare 6, Boyle 5, Cleary 6, Gannon 6, Shields 5, Flores 7, Leahy 7, McEleney 5, Duffy 5, McMillan 5.. subs: Wynne N/A, Gartland 5, Mountney 5, Colovic N/A, Kelly 5.
Arsenal: Runarsson 5, Chambers 7, Pablo Mari 6, Mustafi 6, Soares 7, Smith-Rowe 6, Maitland-Niles 6, Elneny 7, Willock 7, Nketiah 8, Pepe 7.. subs: Ceballos 5, Balogun 8,
12' - GOAL! Dundalk 0-1 Arsenal (Nketiah): It was coming! Nketiah has looked lively and deservedly opens the scoring for Arsenal. He charges down Boyle's attempted clearance, pounces on the loose ball and coolly dinks it over Rogers for his fifth goal of the season. Believe it or not, that makes him the club's top goalscorer!
18' - GOAL! Dundalk 0-2 Arsenal (Elneny): Oh my, what a strike from Elneny! He picks it up 30 yards out and he catches the shot ever so sweetly, leaving the goalkeeper with absolutely no chance with a thunderous effort that arrows into the top right corner.
22' - GOAL! Dundalk 1-2 Arsenal (Flores): Oh, hello - Dundalk have one back! A moment to cherish for the former Wigan player Flores. He plays a neat give-and-go with Duffy and hammers it past Runarsson, who perhaps should have done better.
45'+1 - Dundalk nearly equalise! McEleney's floated cross drops between Arsenal's centre-halves, giving Leahy a fantastic chance to level the scores. But Chambers makes an important recovery, blocking his shot and denying a certain goal!
67' - GOAL! Dundalk 1-3 Arsenal (Willock): That will seal it! It has been a lacklustre performance from Arsenal but they're out of sight now. Balogun shows great strength and vision to hold the ball up and then play the right pass to Willick, who pokes it home.
80' - GOAL! Dundalk 1-4 Arsenal (Balogun): The youngster grabs the goal his performance deserves! On as a substitute, he has made quite the impression, and he makes no mistake when released through on goal by Pepe, placing it past Rogers with a composed finish.
85' - GOAL! Dundalk 2-4 Arsenal (Hoare): Dundalk have a second! Hoare scores his first goal in European football as Arsenal switch off defending a set-piece. Flores whips a free-kick into the box and Hoare rises above everyone to head past Runarsson.
- Joe Willock is the first Arsenal player to register both three goals and three assists in a European campaign for Arsenal since 2016/17, when both Alexis Sánchez and Mesut Özil did so in the Champions League.
- All three of Mohamed Elneny's goals for Arsenal have been scored in European competition (1 in CL, 2 in EL), with two of those strikes coming outside the box.
- Eddie Nketiah scored his fifth goal of the season for Arsenal - he is now Arsenal's top scorer in all competitions this season.