Saturday’s defeat by the same scoreline at home to Brentford had all-but condemned Spurs to either the Europa Conference League or a year without any European football - and that was made official jsut 24 hours later.
Seventh host sixth as Brighton travel to Aston Villa, who are one point ahead of Tottenham and three back from the Seagulls, knowing that the Conference League is their only path to Europe given Brighton’s significantly better goal-difference.
It means Spurs’ 13-year streak of qualifying for European football is under serious threat. Six of those years have been spent in the Champions League, alongside six in the Europa and one in the Conference League.
They went ahead in the 29th minute through Ferguson's powerful effort, which squirmed under Southampton goalkeeper Alex McCarthy.
A moment of individual brilliance from Mitoma doubled Brighton’s advantage 10 minutes later, as the Japan international outmuscled Romeo Lavia on the left wing before setting up Ferguson with a pinpoint cross with the outside of his boot.
Mohamed Elyounoussi pulled one back for Southampton in the 58th minute, but any hopes of a comeback were quickly snuffed out by Pascal Gross, who cut inside onto his left foot and fired a low shot past two defenders inside the near post to wrap up the win and qualification for Europe in the process.
Additional reporting by Reuters.