Boavista - 0 Celtic - 1: UEFA Cup semi-finals, second leg: Henrik Larsson struck his 40th goal of the season late on to fire Celtic into the final of the UEFA Cup with a dramatic victory over Boavista in the Bessa Stadium last night.
Martin O'Neill's men knew they had to produce the magic of Anfield to make their first European final since 1970, but time looked to be running down on their dream.
However, despite missing a glorious first-half opportunity, the Swedish international once again saved the day with a cool finish to send them on the way to Seville on May 21st.
It was all the more satisfying after Boavista boasted Celtic had no chance - but the Scottish Premier League champions proved again that it is dangerous to write them off with another away goal in Europe.
After scoring in Celta Vigo, Stuttgart, Liverpool and Blackburn, it was Larsson who continued their impressive run and end the league misery suffered at Hearts on Saturday.
But goalkeeper Robert Douglas was also heroic, after a couple of fine saves, along with striker Chris Sutton who came on early for Paul Lambert despite not playing since breaking his wrist in the Scottish Cup final.
Celtic pressed from the first minute and were the better side throughout, however, it was the 75th minute before O'Neill sacrificed defender Jos Valgaeren for an attacker in Jamie Smith.
The Northern Irishman's move paid off in the 79th minute when Larsson made up for his earlier miss to put Celtic ahead and grab them an away goal.
The Swede had fortune on his side as Sutton's intended pass broke off the defender into his path and he slotted the ball past Ricardo, who got a hand to it, but could not keep it out.
Celtic breathed a sigh of relief in the 86th minute when Jocivalter went down theatrically in the box under the challenge of Agathe.
But referee Ivanov waved play on before sparking wild celebrations with his full-time whistle as Boavista were denied an all-Porto final in Seville.
Celtic captain Paul Lambert admitted the UEFA Cup final outstrips the Old Firm derby for importance.
The Scotland international, who has a Champions league winners' medal from his time with Borussia Dortmund, believes Sunday's clash at Ibrox cannot compare to the clash against Porto in Seville next month.
But Lambert has an injury concern for the Ibrox showdown after an ankle injury forced him out of the game early on.
"I twisted it and it has swollen up a wee bit so it was better to come off and have 11 fit guys on the field," he said.
"This is the most important game of the season. Whatever happens on Sunday will happen, but the final of this is the one you want.
"I don't think the guys will realise what they have done until the day of the final. Once they are there, it will be fantastic - the game of their lives.
"You never know, against Porto it is a one-off game and we can take anybody."
The Celtic manager was equally ecstatic about the result. "It's fantastic - a really great feeling," O'Neill said. "Over the two games we deserve it - they were so negative with their diving and time-wasting, and it came back to haunt them eventually.
"We saw the fourth officials because all the spare balls disappeared - but after we scored there were plenty of them around. I'm delighted for everyone at the club, the players and the supporters - to be perfectly honest the only people we could hear were our supporters.
"It's about the players and the supporters - I've always said it's about those who pay and those who play.
"I'm thrilled to bits, and for John Robertson (assistant manager) and Steve Walford (first team coach) - the whole backroom staff have been absolutely wonderful."
Midfielder Neil Lennon believes reaching the UEFA Cup final represents a personal defiance to those who have criticised him this season.
The former Northern Ireland international was the subject of a death threat last August and was booed by a small section of the Parkhead crowd during the first leg against Boavista.
"I feel like a boxer who has taken all the punches and is still standing," Lennon said.
"I have had it from everybody - death threats, the lot. But this is a culmination of sticking in there and the manager has shown a lot of faith in me and I'm delighted for him as well.
"It is a fantastic feeling and a lifetime's ambition for all the boys. We thoroughly deserved it on the night.
"We tried to make all the running, but they were breaking things up and diving as much as they could. Then the man Henrik turned up and scored again and we just had to hang on at the end.
"It was very frustrating. The grass was sticky and the ball wasn't running as true as it normally would but we stuck at it."
BOAVISTA: Ricardo, Mario Loja, Avalos, Eder, Erivan (Jocivalter 80), Anunciacao, Martelinho, Pedrosa (Yuri 84), Pedro Santos, Silva (Luiz Claudio 68), Duda. Subs Not Used: William, Rui Oscar, Bosingwa, Goulart. Booked: Avalos.
CELTIC: Douglas, Valgaeren (Smith 75), Balde, Mjallby, Agathe, Lennon, Petrov, Lambert (Sutton 34), Thompson, Larsson, Hartson. Subs Not Used: Marshall, Sylla, McNamara, Laursen, Maloney. Booked: Agathe, Mjallby. Goals: Larsson 80.
Referee: V Ivanov (Russia).