By Josh James at Emirates Stadium
First-half goals from Jordy Clasie and Ryan Bertrand were enough to knock a much-changed Arsenal side out of the EFL Cup.
Clasie gave Emi Martinez no chance from 20 yards inside the opening quarter of an hour, and near the end of a fairly uneventful first half, Bertrand forced home the second from the edge of the box.
Arsenal improved after the interval, repeatedly getting at the Southampton defence, but Fraser Forster proved a difficult hurdle to overcome.
So Arsenal's cup run, as well as the unbeaten run which had stretched back to the opening day of the season, is over.
Setting the scene
A place in the last four of the League Cup – for the first time since 2011 – was the prize if Arsenal could extend their unbeaten sequence to 20 matches.
The Gunners had already seen off Southampton once during that undefeated run, back in September, but it was a very different team that lined up for the EFL Cup game this time around.
The boss reverted to his 'regular' League Cup side – making 10 changes from the side that beat Bournemouth at the weekend. Only Mohamed Elneny retained his place, with Francis Coquelin alongside him in midfield.
The main point of interest was the return of Lucas up front, making his first appearance since picking up an injury in the previous round against Reading.
As usual in this competition, Kieran Gibbs wore the captain's armband.
Southampton named a strong looking line up, including Shane Long up front, who scored twice against the Gunners last December.
After a minute's silence in honour of the victims of the Chapecoense air disaster, the match kicked off in near freezing conditions at Emirates Stadium.
It took a while for the action to warm up. Lucas was looking busy up front, making some incisive runs, but after a low-key start, it was the visitors who took the lead from the first meaningful attack of the game.
Bertrand escaped down the left and sent in a dangerous ball for Sofiane Boufal. His shot was cleared only as far as Clasie, whose first-time shot from the edge of the area whizzed past Martinez.
The goal at least served to spark the game into life.
The tempo picked up and Alex Iwobi and Reine-Adelaide began to see more of the ball.
The Saints were proving difficult to break down though, defending in numbers and soaking up the pressure. Fraser Forster and Virgil van Dijk were equal to anything sent into the area.
The task facing Arsenal got even bigger late on in the half.
After more promising build up play on the left wing, the ball fell to Bertrand just outside the box. He shifted it on to his left foot before squeezing a low shot just inside Martinez's left-hand post.
There was further bad news just before the whistle when Elneny was unable to continue after a continued struggle with sickness, leading to the introduction of Granit Xhaka.
Arsenal needed to lift their level, and they duly showed much more intensity in the early exchanges of the second half.
Iwobi and Ramsey combined well to release Lucas in the box, but his shot from a narrow angle was tame, allowing Forster to gather comfortably.
Moments later Carl Jenkinson crossed for Ramsey in the box, but again the shot lacked power, and Forster held on.
The signs were positive though, after a lackadaisical first half.
Xhaka tried his luck from a free-kick fully 30 yards from goal, and while he struck it sweetly enough, it was straight at Forster.
The game, befitting a knock-out cup encounter, was now much more open, and the two teams began to trade blows. Boufal and Sam McQueen went close for the visitors, before Xhaka, Lucas and Coquelin all tried long-range shots.
The Saints were looking for that knock-out blow, and Shane Long almost delivered it, only to shoot wide when one-on-one with Martinez.
Arsenal were not going to go down without a fight though. Alex Oxlade-Chamberlain, Gibbs and Iwobi all made Forster work as time began to run out.
Ainsley Maitland-Niles scrambled one off the line as Arsenal committed more men forward, but the Gunners' attacking efforts were in vain.
Referee: Kevin Friend
Copyright 2023 The Arsenal Football Club Limited. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source.