Arsenal dangerously threatened twice through Martin Odegaard in the 25th and 26th minutes. However, first the goalkeeper made a fantastic save from his powerful strike, and then the Norwegian shot wide from a promising position.
Southampton quickly punished Arsenal's missed opportunities. In the 35th minute, Ross Stewart expertly met a cross and with a precise shot into the bottom right corner, he scored, sparking an eruption of joy in the stands and a 1-0 lead.
Southampton came close to doubling their advantage, but Leo Scienza's excellent strike from the edge of the box hit the crossbar in the 62nd minute.
In the 68th minute, Viktor Gyökeres came on for Gabriel Jesus, which proved to be a masterstroke. Just eight minutes later, Kai Havertz provided the assist, and Gyökeres routinely finished from close range to equalize at 1-1.
And just when it seemed the match could be heading into extra time, the home manager made the move of the game. Shea Charles entered the pitch in the 76th minute and became the match hero in the 85th. Charles received a pass in the box and coolly scored to give Southampton a new 2-1 lead.
The score did not change until the end of the match, and Southampton secured a place among the top four teams in the world's oldest football competition.
Result and scorers: Southampton – Arsenal 2:1 (Stewart 35', Charles 85' / Gyökeres 68')