Craig Bellamy scored the decisive goal against his former club as Liverpool reached the League Cup final on Wednesday by beating Manchester City 3-2 on aggregate, prompting manager Kenny Dalglish to go all teary-eyed.
A thrilling semi-final second leg finished 2-2 at Anfield but the advantage carved out in Manchester a fortnight ago booked Liverpool a date at Wembley next month where they will face Cardiff City, another of Bellamy's old clubs.
"It couldn't be a better final for me," Bellamy, who left the pitch to a standing ovation when he was substituted late on, told Sky Sports.
"Cardiff means so much to me, it's where I'm from, I've never played at Wembley and to beat a club like Man City with all the players they have, it was just so fitting for us to get to the final," he added.
City started without striker Mario Balotelli after deciding not to appeal his four-match ban for stamping on Tottenham Hotspur's Scott Parker at the weekend.
Against the run of play, City drew level on aggregate with Nigel de Jong's 31st-minute cracker but nine minutes later Liverpool had their noses in front again when captain Steven Gerrard converted a penalty as he had done in the first leg.
City keeper Joe Hart had kept his side in the game with a succession of excellent saves before Edin Dzeko put the Premier League leaders 2-1 ahead on the night with a 67th minute tap-in.
Seven-times winners Liverpool were not done yet, though, and Bellamy secured their place in the final with a confident finish 16 minutes from time that Hart could do nothing about.
Cardiff had booked their place by beating fellow Championship (second division) Crystal Palace 3-1 on penalties on Tuesday after a 1-1 aggregate result.
Victory gives Liverpool the chance of their first silverware since the 2006 FA Cup and provides them with a first trip to Wembley since 1996 as various finals were held at Cardiff's Millennium Stadium while the London stadium was being renovated.
Liverpool manager Dalglish's eyes were brimming with emotion at the final whistle.
"I'm just delighted with all the effort and commitment ... We'll just enjoy the moment," he said.
With their one-goal lead from the first leg in Manchester a fortnight ago, Liverpool looked the hungrier team from the outset and Hart was kept busy as he saved well from Jose Enrique, Charlie Adam and Bellamy early on.
City's defence again sorely missed suspended Vincent Kompany with understudy Stefan Savic looking out of his depth before his halftime substitution.
However, with much of the action at the other end of the pitch, the visitors' opener came out of the blue.
David Silva played a short pass to De Jong who curled the ball into the top corner from 25 metres out despite slipping over while he was striking it.
Liverpool refused to dwell on the setback and were back in front after referee Phil Dowd pointed to the spot following an unlucky handball by Micah Richards, who was hit on an outstretched arm by the ball which had come off his leg.
Gerrard stepped up to take the penalty and got the better of England team mate Hart to send the ball into the bottom corner.
The Premier League leaders got themselves level again on aggregate when Aleksandar Kolarov's exquisite cross from the left in the 67th minute was met by Dzeko at the far post.
Mancini, who sat impassively while his staff celebrated the goal, might well have known what was around the corner having seen his side quickly squander a lead as recently as Sunday in the win over Spurs in the Premier League.
After a quick one-two with Glen Johnson, Bellamy slid the ball past Hart to send Anfield into wild celebrations.
Mancini was left disputing the penalty, while also reckoning City should have had one of their own in the 16th minute when Dzeko was clipped by Adam.
"It was not a penalty for Liverpool but it was a penalty for us on Dzeko, this changed the game," said Mancini, whose sole chance of a domestic trophy this season lies with the Premier League, where his side are three points clear at the top.
"After we did well, we scored, we did some mistakes because we conceded a second stupid goal but now it's finished. Football is football, there are other things more important in life."