Manchester City were given an almighty FA Cup scare by Southampton but came from behind to win 2-1 and make the final for the fourth year in a row.
Championship high-flyers Saints kept City at bay and then delivered what looked like a famous FA Cup moment when Finn Azaz curled them in front with 11 minutes remaining.
However, City kept on knocking on the door against a stubborn Saints defence and Jeremy Doku's deflected effort on 82 minutes drew them level.
Extra-time looked on the cards but Nico Gonzalez produced a moment of Premier League quality to win the game with a rasping strike from 25 yards that flew into the top corner.
For a few minutes Southampton dreamt of emulating their 1976 cup heroes by booking a return to the final on the 50th anniversary of that triumph but it was City's treble quest that remained alive.
City will play either Leeds or Chelsea in the final whilst Southampton are back into the heat of a Championship promotion race where they face Ipswich in midweek.
Your Site' Zinny Boswell at Wembley Stadium:
"This game exploded into life in the final 20 minutes to produce a stunning finale.
"It was absolutely heartbreaking for Southampton, who produced a dogged defensive display. Their 20-match unbeaten run coming to and end along with their FA Cup dream.
"City would have hoped for a less taxing game with respect to managing minutes for the Premier League title run-in, but to have responded in that manner will be huge for their momentum.
"Guardiola's changes, Doku in particular, really swung the game in their favour and puts them in touching distance of a domestic treble. That would be quite something in a season when many had ruled them out."
Put to him that City are on the brink of a domestic treble, Guardiola said: "No, too much. That is far away.
"Before the [FA Cup] final and before the Aston Villa game [the last game of the Premier League season] I will tell you if there is a chance. Now it's not. Far, far away.
"It's important to have three days off for the players, and I told them, so don't think about football. Rest. Then we start a season of five games plus the final of the FA Cup."
Southampton boss Tonda Eckert looking ahead to Tuesday night against Ipswich:
"It's going to be a test of maturity for us to put this game to bed as quickly as possible, because we need another top performance on Tuesday.
"We need to make some decisions for the game on Tuesday, we dive into it a little bit more throughout the day tomorrow and I'm sure that we have a very good team on the pitch that is ready to perform.
"I think if you start to create momentum as a team and as a group. I think that you need to do everything to win games for football. I think that sometimes gives you more energy than trying to save a player and save five per cent here or there.
"It's relentless at this part of the season. The approach has always been the same. We try to put the best team out there that we think gives us the highest chances of winning a game of football and that's not going to change."
