It marked the start of a six-match unbeaten run in the Premier League for Sherwood's side. This weekend, Spurs will be again looking to use victory against Mauricio Pochettino's Saints as a catalyst for another good run.
The abject nature of Spurs' recent losses to Chelsea and Benfica marked the low point of Sherwood's reign as manager thus far. As bad as they were, though, subsequent performances versus Arsenal, and in the second leg against the Portuguese, have been much improved.
By the end of Thursday's Europa League game, which finished 2-2 with Nacer Chadli scoring a brace, Spurs were looking and, evidently, feeling a whole lot more confident. Sherwood told their official website:
"Magnificent" is a bit of a stretch, but the Spurs' boss' general sentiment is not misplaced.
The restored work ethic against Arsenal was retained, but this time with extra quality in front of goal—although it took Harry Kane's second-half introduction to spark the latter into fruition with his combinations with Chadli.
The defensive lapse in concentration that allowed Ezequiel Garay to put Benfica in front was disappointing. But deputising centre-back duo Zeki Fryers and Sandro were hardly to blame and otherwise instilled a sense of security that bodes well for Spurs tightening up at the back again.
Of course, all of this could come undone if the same attitude and a renewed focus is not displayed against Southampton. They have won two games in a row, and striker Rickie Lambert told BBC Sport the currently eighth-placed team still hope to overhaul Manchester United.
Sherwood will likely restore Hugo Lloris in goal as his last line of defence in stopping Lambert and company.
Jan Vertonghen will almost certainly be back after his European suspension, whilst Sky Sports report Younes Kaboul should be fit to start, too. After fine work from their back-ups and Michael Dawson not far off a return, little short of an impeccable display from the centre-backs will be tolerated given their recent disappointing displays.
Either side of them, Kyle Naughton and Danny Rose should continue at right and left-back respectively.
Further forward, Sherwood may look to take the game to Southampton as his team did back in December with two out-and-out strikers up top. Chadli's two good performances this last week might be enough to convince his manager he can do a sufficient supporting job from attacking midfield.
In which case, Sandro should be back in defensive midfield to partner with Nabil Bentaleb. Andros Townsend was quiet in Portugal but played well against Arsenal and may be handed a further chance to impress. Having been rested on Thursday, Christian Eriksen could come in for Gylfi Sigurdsson at inside left.
If he is fit in time, Emmanuel Adebayor should drop back in up front. If he is unavailable, do not be surprised to see Kane rewarded for his midweek efforts with a start.
Out of Europe, and with a top-four place looking to be a stretch, the rest of Tottenham's season starts here. Having gotten slightly back on track, it is up to them what they make of it.
Predicted Tottenham line-up versus Southampton: Lloris; Naughton, Kaboul, Vertonghen, Rose; Townsend, Sandro, Bentaleb, Eriksen; Chadli; Adebayor.