Hugo Ekitike scored the winner and was immediately sent off as a much-changed Liverpool side edged out Southampton 2-1 at Anfield to reach the fourth round of the EFL Cup.
Despite holding their own for 40-odd minutes, the Saints were dealt the harshest of lessons in converting chances towards the end of the first half, where Adam Armstrong clipped the bar when one-on-one with Giorgi Mamardashvili before Leo Scienza headed the follow-up wide.
Just 38 seconds later, a howler at the back from Will Still's men led to Isak giving the hosts the lead with his maiden Liverpool goal, but the Swede's teammates failed to replicate his teammates' ruthlessness in the second half and were made to pay for it.
Arne Slot's found themselves at sixes and sevens from a Southampton corner, allowing Shea Charles to crash home the equaliser, but the customary late Reds winner soon arrived via the boot of Ekitike.
The French forward was dismissed just seconds afterwards, having removed his shirt in celebration while already on a yellow card, but the hosts' 10 men did not have to survive any other scares en route to round four.
SPORTS MOLE'S VERDICT
Death, taxes, and Liverpool scoring a winning goal in the final 10 minutes.
The Reds had seemingly bucked that trend against Everton at the weekend, but with a collection of second-string players and a less-than-100% Isak among the starters on Tuesday, they could be forgiven for needing another late intervention.
However, Ekitike's crucial 86th-minute tap-in will no doubt be overshadowed by his moment of pure lunacy; the striker seemingly forgot he was already on a warning, but Jeremie Frimpong did not, screaming "You have a yellow card!" at his teammate during the celebrations.
Ekitike will now miss this weekend's Premier League clash with Crystal Palace - Isak full top-flight debut incoming - but he nevertheless carried the record 10-time winners through a tricky third-round tie.
Will Still's Southampton clearly believed that a giant killing was possible, and while it did not quite come off, Tuesday's spirited display should be a precursor to improved Championship fortunes.
LIVERPOOL VS. SOUTHAMPTON HIGHLIGHTS
Alexander Isak goal vs. Southampton (43rd min, Liverpool 1-0 Southampton)
Alexander Isak opens his account for Liverpool! ✅ pic.twitter.com/bth0Kq6yJU
— Sky Sports Football (@SkyFootball) September 23, 2025
And that is what happens when you fail to take your chances at Anfield!
Thirty-eight seconds after Southampton spurn two golden chances to take the lead, Liverpool's new £125m man makes no mistake as he scores his first goal in Merseyside red.
Alex McCarthy is at fault, as the goalkeeper's pass to Joshua Quarshie is cut out by Federico Chiesa, who immediately squares for Isak to sweep home from close in.
Shea Charles goal vs. Liverpool (76th min, Liverpool 1-1 Southampton)
Mistakes galore from Liverpool as Shea Charles puts Southampton level at Anfield ? pic.twitter.com/wnVEqzPNRk
— ITV Football (@itvfootball) September 23, 2025
Well, that was a mess.
Wataru Endo makes a complete hash of trying to head a corner clear, and the ball falls kindly for Quarshie on the edge of the six-yard box.
The defender immediately hooks the ball round for substitute Charles, who is being played onside by Conor Bradley and cannot miss from a few yards out.
Hugo Ekitike goal and red card vs. Southampton (85th min, Liverpool 2-1 Southampton)
Hugo Ekitike puts Liverpool back in front!
— Sky Sports Football (@SkyFootball) September 23, 2025
The forward is sent off for a second bookable offence after taking his shirt off in celebration! ? pic.twitter.com/zLvbU9R4kh
What a way to retake the lead! And what a way to get yourself sent for an early bath!
Andy Robertson sends a defence-splitting pass through to Federico Chiesa, who has Ekitike alongside him and squares to the Frenchman for a simple finish.
However, Ekitike - who was already on a yellow card - foolishly removes his shirt in celebration and takes the walk of shame for a second bookable offence!
MAN OF THE MATCH - FEDERICO CHIESA
Praises go to Giovanni Leoni - one hopes his injury is not as serious as it appeared - and Giorgi Mamardashvili, but Federico Chiesa takes this accolade for his pivotal playmaking.
The Italy international set up both of the hosts' goals on the evening, and if he can stay fit, Liverpool can breathe easy when Mohamed Salah jets off to the Africa Cup of Nations.
LIVERPOOL VS. SOUTHAMPTON MATCH STATS
Possession: Liverpool 61%-39% Southampton
Shots: Liverpool 10-13 Southampton
Shots on target: Liverpool 4-3 Southampton
Corners: Liverpool 3-6 Southampton
Fouls: Liverpool 8-12 Southampton
WHAT NEXT?
Liverpool will soon discover their opponents for the fourth round of the EFL Cup; the draw takes place on Wednesday following the remaining third-round fixtures.
League-wise, the Reds head to Crystal Palace in the Premier League this Saturday at 3pm, while Still's men welcome Middlesbrough to St Mary's in Championship action at the same time.