Kane, going into Tuesday's clash with the Saints, was level on Alan Shearer's 1995 calendar year record of 36 strikes but quickly broke the record with a close-ranger header in the 22nd minute.
The England worldwide, who has made history in just 36 appearances compared to Shearer's 42 for Blackburn in 1995, put Spurs into a two-goal half-time lead with a close-range header and a simple tap-in before completing his second successive hat-trick with a dinked finish over Saints goalkeeper Fraser Forster for his side's fifth.
Any glimpse of optimism from Southampton were all but instantaneously extinguished as Kane completed his second hat-trick in three days, Alli released the striker through on goal with Forster quick off his line and just coolly lofted over his compatriot to complete his eighth trio of the calender year.
Jamie Redknapp and Thierry Henry joined David Jones to analyse the talking points from Tottenham's 5-2 home win over Southampton on Boxing Day. That tally means he has scored more hat-tricks in 2017 than Lionel Messi, Cristiano Ronaldo, Robert Lewandowski, Sergio Aguero and Edinson Cavani combined.
His first goal came from the penalty spot after a controversial decision to give a foul on Dele Alli when there was only minimal contact.
7 Got his seventh hat-trick of the year on Saturday. You deserve to hold the record of most @premierleague goals in a calendar year. Alli now has four assists and a goal in two games and looks back to his best, while Eriksen was the architect of the hosts' best moves.
At both ends, they were missing key players but their lack of organisation and fight was embarrassing, proving far more costly than the absences of Virgil van Dijk and Charlie Austin.
Mauricio Pochettino said Kane's tally was just reward for the effort he has put into his game. Even during my time at Spurs I'm surprised by him.
Saints visit Manchester United on December 30 and barring a shock, they're likely to start 2018 in the relegation zone or just above it. Saints did the opposite, backing off Son, Alli and Eriksen naively and allowing Spurs to pick them off at will.