Sherwood jumped in jubilation on the touch-line. White Hart Lane erupted. Gylfi Sigurdsson, with his stunning volley in stoppage time, resurrected Tottenham's perilous season, blighted by recent disappointments.
The Icelandic midfielder arrowed the ball beyond the despaired reaches of Artur Boruc to spark raptures of wild celebration from the home support. They deserved this, having been made to dismally suffer in weeks of late as an outpour of relief reverberated around the Lane.
Their crucial victory was reward for their resilience and desire, fighting back from two-nil down through Christian Eriksen's brace. Southampton had looked set to secure their first victory at White Hart Lane in eleven years after goals from Jay Rodriguez and Adam Lallana had put them firmly in the driving seat, but Spurs refused to give up, responding positively to Sherwood's recent doubts about their guts.
Younes Kaboul, sporting the captain's armband, led by example. Returning from injury, the Frenchman barked orders and set the tone with a assertive display, even sweeping past four Saints players to stifle the danger present. Roberto Soldado showed glimpses of justification for his £26m price tag with some sublime contributions, shrugging Dejan Lovren of the ball as Eriksen netted his second goal. Eriksen was outstanding, inspiring the remarkable comeback with his nimble creativity.
Sherwood began his managerial career with a 3-2 victory at St Mary's in December, and this one over Mauricio Pochettino's side was no less significant. That game earlier in the season was an audition. Here, months later, it was an audition to retain his employment.
As Sherwood condemned himself to watching from the stands, after revealing his family's embarrassment at his passionate touch-line antics, the former Spurs midfielder looked as his defence deployed a precarious high-line, catching Lambert and Rodriguez off-side. But the latter would not be denied moments later.
From Boruc's goal-kick, Naughton decided in taking a gamble. As the ball hung in the air, the young right-back excessively committed himself to intercepting its flight, and when he misjudged his jump, Rodriguez was left un-marked to open up his body and side-foot beyond Lloris. It had been coming - Spurs were taking too many treacherous chances with their defending.
The Saints were in the ascendancy, Lloris easily gathering Lallana's feebly-struck effort before Luke Shaw's deflected shot drifted just wide.
Pochettino's men were controlled and composed in possession, producing a wonderful away display, delighting their ardent visiting support who had made the lengthy trek from the South Coast, further increasing their gratification when Lallana poked past Lloris.
Naughton was once again at fault, stumbling over the ball and subsequently allowing Lambert to thread in Lallana, who had made a great run, on his right. Southampton were two-nil up. White Hart Lane groaned collectively.
Sherwood descended upon the touch-line, his presence seemingly injecting some much-needed urgency and purpose in his side's otherwise apathetic display. Eriksen's close-range drive through Boruc's legs came courtesy of another woeful defensive error, Clyne the offender on this occasion. From, coincidentally, Naughton's cross, Clyne ruefully lost his concentration for a spilt second, taking his eye of the ball as Eriksen lurked behind him, taking full advantage of the terrible error.
After Boruc had palmed over Eriksen's free-kick, Spurs moved into half-time with hope, and emerged for the second-half with much more attacking vigour. Lovren, in all honesty, should have been stronger. After Soldado, without much labour, shrugged the Croatian defender off the ball, the Spaniard rolled the ball across the goalmouth, with Eriksen gleefully tucking home the hosts' equaliser. Belief, and relief, reverberated around the Lane.
Both sides went for the victory. Callum Chambers heroically blocked Eriksen's effort at goal before Lambert, after outstanding build-up play, headed over the bar. Then Sigurdsson stepped up.