Former European champions Celtic and Porto will meet in the UEFA Cup final in Seville on May 21 after contrasting semi-final victories on Thursday.
Celtic, the first British side to win the European Cup in 1967, made it through to their first European final for 33 years when a late goal from Swedish striker Henrik Larsson gave them a 1-0 win over Porto's city rivals Boavista in Oporto for a 2-1 aggregate win.
That made up for his penalty miss in the first leg in Glasgow two weeks ago.
Porto, who won the European Cup in 1987, qualified for their first European final since then with a determined rearguard action in Rome where they held Lazio to a 0-0 draw to advance 4-1 on aggregate.
They came through unscathed after Claudio Lopez missed a 57th-minute penalty for Lazio which Porto goalie Vitor Baia pushed away to safety.
But Porto will be without forward Helder Postiga in the final after he was sent off with Lazio's Cesar just before halftime for squaring up to each other after both had been booked earlier.
Thursday's two matches could hardly have been a greater contrast to the two Champions League quarter-finals played on Wednesday which produced 12 goals between them.
The four teams playing on Thursday barely mustered 12 goal attempts between them.
O'NEILL DELIGHTED
Still, the Celtic players and their fans did not care about that and celebrated wildly at the end of the game at the Do Bessa stadium which is being re-built in time for next year's European Championship finals.
The half-built stadium lent an eerie atmosphere to the game which was awful to watch with poor passing from both teams and a minimum of goalmouth action.
Boavista, who held the away-goal advantage after their 1-1 draw in Glasgow, were content to play out time almost from the start -- but they failed, finally succumbing 11 minutes from time.
That was when the match produced its only moment of true quality leading to Larsson's 40th goal of the season.
A ball played up to John Hartson was intercepted by defender Filipe Anunciacao who inadvertently turned it straight into Larsson's path. The Swede controlled with his right foot and smashed it past diving goalkeeper Ricardo with his left.
Celtic manager Martin O'Neill, a European Cup winner with Nottingham Forest in 1980, was delighted afterwards.
"It's fantastic, a great feeling. We deserved it. Boavista were so negative, wasting time, and it came back to haunt them. I am delighted for the players, the supporters, for the whole club. It was a magnificent effort all told," he said.
Celtic's last appearance in a European final came 33 years ago when they lost to Feyenoord in the European Cup final. The last Scottish side to reach a European final were Dundee United who lost to 1FK Gothenburg in the 1987 UEFA Cup final.
Porto became the first Portuguese club to reach a European final since Benfica made it in the European Cup 13 years ago and they deserved their place after keeping out Lazio in Rome.
Despite the lack of goals the Lazio-Porto match was a far better spectacle than the poor fare on offer in the other game, and Porto had to play well defensively to keep out a determined Lazio in the early stages.
They also held firm when Lazio were awarded a penalty after 57 minutes when Jorge Costa brought down Simone Inzaghi, but Lopez's weak shot failed to beat Baia, who pushed it around the post.