From St Mary's - Southampton required an extra-time winner from Kyle Walker-Peters to beat Championship side Coventry City 2-1 and book their place in the FA Cup fifth round.
Energised by a packed-out away end Coventry started strongly and forced Willy Caballero into action twice in the opening exchanges.
The Sky Blues eventually got a deserved breakthrough in the 22nd minute. A neat one-two with Ben Sheaf set Viktor Gyökeres free in the box and he made the most of his opportunity, lashing an effort into the bottom corner.
An out-of-sorts Southampton offered little in response and Chelsea loanee Ian Maatsen should have doubled his side's advantage on the stroke of half-time, but he dragged his shot wide from the edge of the box.
Saints stepped up the intensity after the break but continued to struggle in the final third. Instead it would be Coventry who looked more likely to score, but their finishing was lacking.
The Sky Blues would be made to rue these missed chances just after the hour mark when Stuart Armstrong levelled things up in scintillating fashion. Picking the ball up 25-yards out, the half-time substitute cracked off a wonderful effort which nestled in the top corner.
Saints were then handed a huge let-off 15 minutes from time when a defensive mixup allowed Martyn Waghorn to race through on goal, only to be denied by the stoic Caballero. That was the last significant action of the 90 minutes, with the game going to extra time.
At first neither side looked like scoring but Saints did find a winner in the second half of the additional period. Kyle Walker-Peters was the hero, cutting in for the left before placing his effort into the bottom corner.
The drama was not done yet though. First, Waghorn nodded a golden chance wide and then Coventry forced the ball over the line, only for the assistant referee to raise his flag after a lengthy delay.
No one was more disappointed that the pitch invader who had to retreat back into the stands with his tail between his legs. It was the perfect end to a thoroughly entertaining cup tie.
Here are your Saints player ratings...
1. Goalkeeper & defenders
Willy Caballero (GK) - 7/10 - Made a few decent stops to keep the scores down, and then pulled off a big save to deny Waghorn at the death. He's still got it.
Yann Valery (CB) - 5/10 - Passing was bit off early on. Chipped in with some important covering in the second half when Saints moved to a back four.
Lyanco (CB) - 7/10 - Performed well before being taken off on the half-hour mark through injury.
Jack Stephens (CB) - 5/10 - Read the game competently for the most part, but caught in no man's land for the opener. Missed a few opportunities to launch counter-attacks too.
2. Wing-backs & midfielders
Tino Livramento (RWB) - 6/10 - Full of energy and always looking to drive into the final third. A few instances of questionable defensive positioning went unpunished.
Ibrahim Diallo (CM) - 4/10 - Tidy in possession but was far too safe at times, slowing his side down when they needed to up their tempo.
James Ward-Prowse (CM) - 5/10 - Nowhere near his best. FInal ball had to be better on several occasions
Thierry Small (LWB) - 3/10 - Started the game nervously and almost diverted a headed back-pass into his own net. Improved a little before being taken off at half time.
Theo Walcott (RW) - 4/10 - Not great. Tried to make things happen but was often sloppy in possession.
Shane Long (ST) - 1/10 - May as well have not been playing. The anti-poacher. 120 minutes and never looked like scoring.
Adam Armstrong (LW) - N/A - Could not do anything right. Deservedly dragged at the break.
Nathan Redmond (LM) - 5/10 - Started strongly, testing Coventry out wide with his direct runs. Faded badly, though.
Stuart Armstrong (RM) - 8/10 - What. A. Goal. He changed the game for his side and is one of the most underrated players in the top flight.
Kyle Walker-Peters (LB) - 8/10 - Scored a vital goal, just like he did against Man City. He clearly loves playing against sky-blue teams.
Armando Broja (ST) - 6/10 - His introduction unsettled the Coventry defence. Finishing was off.
Oriol Romeu (CM) - 6/10 - Added poise in the middle of the park
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