A Gabriel own goal was enough to see Arsenal suffer an FA Cup exit in the 4th round. Southampton going through means they will be facing Wolves at Molineux.
Mikel Arteta made six changes from the side that beat Newcastle on Monday night and some showed why they are not on the team sheet in the Premier League.
Story of the match
It was a slow start from Arsenal and an excellent and dominant start from the Saints with James Ward-Prowse hitting the bar from a corner.
Arsenal had got forward on a few occasions but didn't offer any sort of threat towards the Saints back line and Fraser Forster.
This was the same story until the 24th minute when Mo Elneny lost the ball in a dangerous area which led to Southampton netting the opener by a shot from Walker-Peters and an outstretched leg by Gabriel.
After the opener Arsenal had a job to do with the incoming pressure from Southampton and had to face a few shots from the forward players.
Arsenal were lacklustre and slow from the get go and Southampton took advantage of this.
The half time whistle blew and Arsenal had 54.4 % of possession to Southamptons 45.6%. The saints had a total of seven shots and Arsenal only had just three.
The second half
Arsenal fans were hoping for a few changes from Mikel Arteta but this was not the case, the same players came out for the second half and didn't have a good start with Southampton piling the pressure on early on and leading the Gunners into making mistakes.
It took Arteta until the 58th minute to make the changes with Gabriel Martinelli and Elneny coming off for Thomas Partey and Bukayo Saka.
A big chance fell to Rob Holding in the 59th minute when the ball dropped nicely to him six yards out but he blazed over the bar.
The subs made an impact as Arsenal started to pile on the pressure onto Southampton with Nicolas Pepe feeding a ball through to Eddie Nketiah, only for Forster to divert the shot for a corner.
Arsenal had hope for a penalty in the 70th minute when a cross from the right strikes Walker-Peters on the hand but after a quick review nothing came from it.
Alexandre Lacazette coming on for Hector Bellerin showed Arsenal were going all out to try and get an equaliser but didn't manage to level things out.
With 20 minutes remaining Arsenal tried to put Southampton under pressure but the Saints back line held tight until the final whistle.
With only days left in the window it clearly shows Arsenal are short in some positions and lack creativity without Emile Smith Rowe in the side.
This proves to be a vital few days left in the January transfer window to sort things out.
Arsenal travel back up to St Marys on Tuesday for Premier League action with the Gunners set to start with the same team that beat Newcastle just a few days ago.