Tottenham have so far gifted Crystal Palace and Ipswich their first victories of the season, but any inclination that the team's tendency to gift points to lower table sides was quickly put to bed with five first half goals.
The first came through vice-captain James Maddison inside 36 seconds, Tottenham's quickest Premier League goal since 2018. Djed Spence, who made his first top flight start for the Lilywhites, cleverly turned his marker on the half way line and accelerated towards the Southampton penalty area, before slotting through his compatriot who calmly finished through the legs of Alex McCarthy.
Boos echoed around St. Marys for under siege Russell Martin, as Southampton's defence carelessly gave away another two goals in quick succession courtesy of Son Heung-Min and Dejan Kulusevski.
The home side made a substitution after just quarter of an hour and reverted to three at the back, but the onslaught continued, with Pape Matar Sarr scoring his fourth goal of the season with a well taken finish, after maneuvering his way through the lacklustre Saints defence in the 25th minute.
Maddison added a fifth on the stroke of half time, with an incredible, powerful right-footed shot from a tight angle, to stun the already infuriated Southampton fans.
The home side managed to hold out in the second half to avoid what many feared could have been another humiliating and record equalling or record breaking defeat - having lost 9-0 twice in the past five years.
The result will significantly boost the confidence of Ange Postecoglou's side, who were winless in five prior to kick-off.
The win will no doubt increase their hopes of beating Manchester United in their vital League Cup quarter-final clash on Thursday, as they desperately aim to end their near 17 year trophy drought.
Tottenham Player Ratings
Fraser Forster - 8
Forster returned to his former club with his sights set on continuing his fine run of form, since stepping in for the injured Guglielmo Vicario.
The Englishman did just that, although not tested too often, Forster was worked on a few occasions in the second half and was secure in his handling when called upon.
Djed Spence - 9
The number 24 really seems to have revitalised his Tottenham career, after multiple loans spells and strong links of a permanent move away.
Spence's impressive assist was followed up with a solid defensive display, also maintaining possession well while under high press, when playing out from the back.
Radu Dragusin - 8
Dragusin commanded the thin Tottenham defence with authority and often cleared the danger after the sparse Southampton attacks.
Archie Gray - 9
The 18-year-old deserves so much praise. Gray has had limited opportunities since joining in the summer, but when called upon to play in a completely unfamiliar centre back role, has really stepped in when his side were in desperate need of a central defender, due to their abundance of absentees.
Destiny Udogie - 7
Tottenham's misery of constantly losing defenders to injury was worsened when the Italian had to be replaced after half an hour.
Until then, Udogie was dominant in winning his duals and it was his tackle to regain possession, which eventually led to his side's third.
Pape Matar Sarr - 8
Sarr made regular interceptions and always looked to advance the play forward after receiving the ball.
The Senegalese midfielder took his goal superbly, dribbling through a tight space between defenders, before poking the ball in with an outstretched left leg.
James Maddison - 9
Maddison continued his pursuit of regaining his international spot, with a fantastic performance. He took his two goals with sublime precision and really acted as the catalyst in every Tottenham attack.
Lucas Bergvall - 8
The Swede impressed during his first Premier league start, making some fine passes and showcasing neat footwork. Sometimes he took a bit too long on the ball and was subsequently dispossessed, but nothing drastic that can't be rectified with practice.
Dejan Kulusevski - 8
Tottenham's player of the season so far was once again fundamental in his side's victory.
Kulusevski caused trouble for the Saints from both the right wing and central midfield and added to his goal tally with a poachers finish.
Domonic Solanke - 6
A frustrating evening for the striker, who would have been desperate to get on the scoresheet.
Son Heung-Min - 9
The South Korean has suffered one of his more difficult seasons in his tenth campaign for the club.
Yesterday however, Son scored his 16th goal against Southampton, netting more against them than any other side. He also registered two assists, making him Tottenham's record assist provider in the Premier League (68).
Substitutes
Pedro Porro - 6
After his introduction in the 28th minute, Porro was rarely troubled in the right back position but was caught on his heels on a couple of occasions.
Brennan Johnson - 5
The Welshman was often wasteful and didn't pose much threat going forward. He also squandered a great opportunity from close range, which he would have been offside for anyway.
Alfie Dorrington - 7
The 19-year-old centre back impressed on his debut, keeping calm in possession and eliminating threat. A great opportunity to gain some experience, especially considering he may be called upon soon, with Tottenham's lack of defensive options.
Timo Werner - 6
After being heavily scrutinised by his manager for his poor performance against Rangers on Thursday, Werner didn't get many opportunities to make amends but also didn't make any mistakes.
Will Lankshear - 6
The young striker linked up play well during his short spell on the pitch.