After a first half that ended goalless, the spectators at Wembley witnessed three goals in the second half and their team's qualification for the final of the competition.
The visitors took the lead through Finn Azaz in the 79th minute, only for Jeremy Doku to equalize for the Citizens just four minutes later.
A dramatic finish ensued, and in the 87th minute, Nico Gonzalez secured the victory for the hosts, scoring after an assist from Doku, who thus capped off his phenomenal performance.
City will face the winner of the other semifinal, where Chelsea and Leeds meet, in the final.
Result and scorers: Manchester City - Southampton 2:1 (Doku 83', Nico 87' / Azaz 79')