Kelechi Iheanacho fired Leicester into their first FA Cup final since 1969 as 4,000 spectators witnessed their 1-0 win over Southampton at Wembley.
Iheanacho's swept finish at the second attempt after 55 minutes was enough to ensure the Foxes progress to face Chelsea. There is expected to be 21,000 in attendance - including far more supporters - when they return to Wembley on May 15 looking to win their first-ever FA Cup.
James Maddison missed two good chances to extend Leicester's lead following his introduction off the bench in front of the watching Gareth Southgate, but one goal was enough for Brendan Rodgers' side.
Southampton last reached the FA Cup final in 2003 but failed to register a shot on target - the best chance falling to Ibrahima Diallo - as their run came to a disappointing end.
Leicester: Schmeichel (6), Fofana (7), Soyuncu (6), Evans (8), Ricardo Pereira (6), Ndidi (7), Tielemans (7), Castagne (7), Perez (6), Iheanacho (8), Vardy (7).
Subs: Maddison (6), Albrighton (6).
Southampton: Forster (6), Walker-Peters (6), Bednarek (5), Vestergaard (6), Bertrand (6), Djenepo (5), Diallo (4), Ward-Prowse (6), Armstrong (7), Redmond (4), Ings (5).
Subs: Adams (6), Salisu (n/a), Tella (n/a), Walcott (6).
Man of the match: Kelechi Iheanacho.
Iheanacho's FA Cup love affair goes on
"The FA Cup loves me, and I love the FA Cup," Iheanacho said afterwards, his goal extending his run to having scored in the last three rounds. His finish was the 14th FA Cup goal of his career while no other player has scored more in the past five seasons.
- Brendan Rodgers restored Ayoze Perez to the Leicester line-up for the FA Cup semi-final against Southampton. The Spaniard was dropped from the squad against West Ham last weekend for hosting a party, with attendees Hamza Choudhury and James Maddison also omitted for that crunch match. The latter pair were on the bench at Wembley, where Perez came into the starting line-up along with Caglar Soyuncu.
- Moussa Djenepo replaced Theo Walcott in Southampton's only alteration.
There was a spine-tingling applause as the teams emerged for kick-off at Wembley, where thousands of fans returned as part of one of the government's pilot events.
- Brendan Rodgers hails 'massive achievement'
- How the teams lined up | Match stats
- Get Sky Sports | Get a Sky Sports Pass
- FA Cup final to be played on May 15
A number of Southampton and Leicester fans were among the 4,000 local residents, including key workers, as the FA Cup semi-final welcomed the biggest crowd in England for 13 months.
Everyone in attendance had to prove they had tested negative for coronavirus in a lateral flow test before coming to the game, which will be followed by a larger crowd at next week's Carabao Cup final between Tottenham and Manchester City.
The first half was low on major incident, but Leicester created the better chances, spurned on both occasions by Jamie Vardy. It took until the 34th minute for the first to arrive as Youri Tielemans pounced on an Diallo mistake in midfield to set the veteran striker on his way but with Fraser Forster coming out to close the angle, Vardy lifted his shot over the crossbar.
Sky Sports' Ron Walker said: "It's a classic Leicester attack. Win the ball back in midfield, get it forward quickly - it's just missing the similarly classic Vardy finish. He gets his dink all wrong. He hasn't scored for Leicester in more than two months; the 34-year-old's confidence is not at its highest."
Vardy may have wondered again how he hadn't found the net a couple of minutes before the break when Jonny Evans' header back across goal from Tielemans' corner was brilliantly taken off his head by Jan Bednarek as the half ended goalless.
Southampton, winners of the FA Cup in 1976, had looked slightly frozen by the occasion; they failed to attempt a single shot at goal in the opening 45 minutes of a match for the first time since November 2019 against Everton in the Premier League - but there was more intensity from Ralph Hasenhuttl's side upon the restart.
Kyle Walker-Peters won a free-kick, which was delivered by James Ward-Prowse onto the head of Jannik Vestergaard but the defender was unable to direct his header on target.
But Leicester would open the scoring after 55 minutes. Vardy's movement on the flank left Bednarek trailing in this wake, with the striker crossing for Iheanacho to shoot goalwards. The ball bounced kindly off Vestergaard and the in-form striker made no mistake with the rebound.
Reporting from Wembley, Sky Sports' Dharmesh Sheth said: "I've no idea what 4,000 fans cheering inside a 90,000 seater stadium is supposed to sound like... but that sounded louder than 4,000 fans cheering inside a 90,000 seater stadium."
There was much greater urgency now from Southampton as Hasenhuttl introduced Che Adams, and after the Scotland striker's shot was blocked by Evans, Diallo was unable to keep his shot down.
He came within a whisker of equalising moments later, however, as he ran onto Wilfred Ndidi's headed clearance to flash a rising volley a yard wide with Kasper Schmeichel stranded.
Maddison was summoned from the bench as Rodgers sought to wrestle back control, and he had the chance to put last week's indiscretion behind him when he collected Iheanacho's pass but his shot was blasted over. Forster watched another Maddison effort sail over but time was running out for Southampton.
There was still not a single shot on target - and that's how it would end. When Ward-Prowse's final corner was claimed by Schmeichel, their wait for a second FA Cup was extended into a 46th year at least as Leicester marched on.
What the managers said
Leicester boss Brendan Rodgers: "It's amazing. The club have been waiting a long time to get to the final. I thought we deserved it. We defended strongly and didn't concede any efforts on goal.
"As the game wore on we looked really bright in our attacking play and maybe should have had more than one goal. (I'm) just really pleased for everyone, the players first and foremost.
"It's a massive achievement, but we have to be hungry and keep pushing. We're embracing the challenge, and the players today were first class. We're certainly not frightened by the challenge.
"It's going to be a privilege to lead the team out in the final. It was always going to be a tight game but I felt we deserved it. We had to defend well, which we did. I'm delighted for the players as they've shown that they're constantly learning.
"The performance was very composed, mature, and we got the goal that counted. I just spoke to Top [Leicester chairman Aiyawatt 'Top' Srivaddhanaprabha] and he's absolutely over the moon. He was absolutely over-joyed. It's the early hours of the morning over there so he's been up all night. To be able to get to the final, I'm very happy for him."
Southampton boss Ralph Hasenhuttl: "We tried a lot and worked a lot against the ball. The performance was absolutely OK. We saw a tight game from both teams with both sides struggling to create chances. We had some moments and won the ball a lot of times in their half.
"We didn't ultimately make the final step or create the final chance so we ended up without a shot on target. Defensively, it was really good what we did today. The goal we conceded was unlucky. He managed to hit our player with his first shot. It's a pity when a goal like this decides a game.
"It was the only goal we conceded in our run this season but we have to come back and fight to win it next year. It was a nice experience playing in this beautiful ground and even with just a few fans, it was a nice feeling. We now have to concentrate on the remaining games of the season. If we put the same effort in against Tottenham on Wednesday then we have a chance of getting something."
Man of the match - Kelechi Iheanacho
Iheanacho is the first Nigerian player to score 15 goals in all competitions in a season for a Premier League club since Odion Ighalo in 2015-16 for Watford, who scored 17.
"It is a dream come true," he told BT Sport. "Loving it. I am happy. We did it together to get to the final. I watched the FA Cup when I was little and now I get the chance to play in the final. Such a big dream for me.
"We did it together as a team. I am proud of that. Really happy. We are really happy to have some fans today, it is not easy with everything going on but hopefully the final there will be a lot more.
"I just want to concentrate and keep working hard. Of course it is amazing when you count the goals but my focus is to keep working hard."
Foxes end FA Cup final wait - Opta stats
- Leicester City have reached their first FA Cup final since 1969, a gap of 52 years, the longest between finals since Portsmouth went 69 and Cardiff went 81 between finals before facing one another in 2008.
- Southampton have now been eliminated in eight of their last 10 FA Cup semi-final appearances, two of which have come in the last four seasons (2017-18 vs Chelsea, 2020-21 vs Leicester).
- This was only Leicester's fourth win in 15 appearances at Wembley (D1 L10) and their first since the 2000 League Cup final against Tranmere, while Southampton have lost eight of their 10 matches at Wembley (W2), losing their last five in a row.
- Since his debut in the FA Cup in January 2016, Kelechi Iheanacho has scored more goals in the competition (first round onwards) than any other player, netting 14 times in 19 games.
Live Premier League
The FA Cup final takes place at Wembley on Saturday May 15 at 5.30pm.
Leicester host West Brom at the King Power Stadium on Thursday in the Premier League; kick-off is at 8pm. Southampton travel to face Tottenham on Wednesday, live on Sky Sports Premier League and Main Event; kick-off is at 8pm.