Going into the match, Claudio Ranieri's men were in excellent form and in fact had managed to rack up three consecutive 1-0 victories, consolidating their position at the top of the Premier League. As it happened, this is how the scores finished at the King Power Stadium on Sunday afternoon as Wes Morgan's first-half header settled the game.
However, it was not a sparkling performance from the home side despite their momentous victory. Nevertheless, who was named man of the match as the Foxes saw their grip on a possible Premier League crown increase?
Kasper Schmeichel - 7/10: Despite not being tested all too much by the Saints, Leicester City's ever-present No.1 still had a fairly decent game. The Dane displayed impressive shot-stopping (specifically palming away a long-range effort from Jose Fonte that was destined for the back of the net) and claimed crosses with confidence well all afternoon. On the other hand, did flap at a few Southampton set pieces that could have cost his team.
Danny Simpson - 8/10: Surely one of the former Newcastle United man's best games for the Foxes. The Englishman was unbeatable all afternoon and it was down to his miraculous block that prevented a certain Sadio Mane opener after he had skipped past the goalkeeper. The likes of Dusan Tadic and the aforementioned Mane were all kept relatively quiet by Simpson. Very impressive.
Wes Morgan - 9/10: An undoubted man of the match for the home side. Even without his game-winning goal, the former Nottingham Forest defender was a major factor as to why his team earned a big victory. The Jamaican was imperious all afternoon; winning his fair share of headers and displayed crucial defensive instincts with clever interceptions and strong tackling.
Robert Huth - 7/10: A quiet yet comfortable game from the German international against Ronald Koeman's men. Like his central defensive partner, he showed some smart defensive instincts, specifically using his immense power to out-strength the Southampton attack. Nonetheless, did look slightly shaky on the ball. Overall though, a job well done.
Christian Fuchs - 7/10: It has been said before but this man is one of the bargains of the summer transfer window. The 29-year-old yet again impressed against the Saints. The Austrian used all of his considerable experience to silence the likes of Sadio Mane - a major factor in his side's defensive prowess. As a matter of fact, the former Schalke man also provided an excellent cross that allowed Wes Morgan to nod home in the closing stages of the first half.
Riyad Mahrez - 6/10: By his usually high standards, this was a poor game from the Algerian. Nothing at all seemed to come off for the former Le Havre man, although that may have been to do with the visitors' unwavering pursuit of the mercurial winger. However, did show some positive attacking intent that went unrewarded. Substituted mid-way through the second period.
Danny Drinkwater - 7/10: Despite being over-ran on a couple of occasions in the centre, Drinkwater followed up his maiden international appearance with another untainted performance. Sitting just in front of the Leicester backline, the former Manchester United trainee gave some valuable defensive support. As always, a good range of passing was also easy to identify in an otherwise combative midfield battle.
N'Golo Kante - 7/10: A standard if not sparkling performance from the French international. As is expected from the ex-SM Caen man, he was an ever-present fixture with his tenacious attitude and affection for a tackle. Like Drinkwater, he was providing some much-needed defensive support for his team, and in fact did at points appear as a useful attacking outlet with his pacey, driving runs into the opposition half.
Marc Albrighton - 7/10: Again, a steady performance from the ex-Aston Villa wide-man. As has become a trademark for Albrighton, he was constantly looking to get a cross into the opposition box. Also, at points he did prove to be a useful asset on the counter attack but sometimes did not select the correct option with his final pass.
Shinji Okazaki - 5/10: Simply put, the Japanese international was off the pace against Southampton. On numerous occasions, the experienced forward was on a different wavelength to the rest of his team mates. Hardly the physical presence Leicester fans have been accustomed to, Okazaki could not get a hold of the ball all afternoon, whether that be in the air or on the floor. Frustrating.
Jamie Vardy - 6/10: Another somewhat lethargic performance from the England international. Despite starting very well and looking extremely motivated for the game with numerous driving runs and clever crosses, he went somewhat off the boil.
On the counter attack, he looked slightly hesitant and lethargic but that may be to do with his commitments on international duty with England. Nonetheless, did have a good chance late in the second half which was well saved by Fraser Forster. Will hope to be back to his best sooner rather than later.
Leonardo Ulloa - 6/10: Came on in place of Shinji Okazaki and seemingly had the desired effect as he provided a far stronger and more dominant presence up front. Challenged the Southampton defence well and seamlessly linked up with the aforementioned Vardy. Not too many chances in front of goal but this was probably down to the constant pressure from the away side in the second half.
Demarai Gray - 6/10: Replacing Riyad Mahrez in the closing stages, the former Birmingham City youngster gave much-needed defensive support for Danny Simpson after coming on. Had some good touches and held the ball well in his relatively short cameo.
Nathan Dyer - N/A: Only came on for a few minutes as the home side looked to close out the win. The on-loan Swansea City winger barely had time for a touch of the ball.