Larsson's late strike is delight for Celtic

Boavista 0 Celtic 1, Celtic win 2-1 on aggregate

Life begins at 40, they say, and the adage certainly held good for Celtic in the Do Besso Stadium here last night. Henrik Larsson's 40th goal of the season settled their Uefa Cup semi-final with Boavista late in a hitherto abject second-leg match, sending the Scottish champions through to their first European final in 33 years.

Only 11 minutes remained when Larsson attempted to play a one-two on the edge of the Portuguese area. Filipe Anuncicacão, attempting to clear, hooked it straight back into his stride, and the Swede's less than brutal shot was touched into the net by Ricardo. Having withstood Boavista's unconvincing retaliation, Celtic and their rapturous followers thus go forward to Seville to play Porto in the final on 21 May.

Martin O'Neill had announced his intention to "go for it", the Celtic manager's boldness informed by the fact that his team had failed to score in only two games all season, in Basel and Inverness.

Similarly, Boavista's recent form must have encouraged O'Neill's optimism. Portuguese champions two years ago, they now stand 12th in their domestic league, 40 points behind their neighbours, Porto, and with only seven wins from 28 matches. That said, Jaime Pacheco's team had dispatched Paris St-Germain, Hertha Berlin and Malaga in earlier rounds, suggesting they were capable of rising to the occasion.

Rising with John Hartson proved problematic for Boavista from the start, the Welshman's aerial strength provoking panic. Pedrosa seemed particularly vexed by his muscular style, putting in some nervous challenges, and allowing Alan Thompson's centre to pass over him in the ninth minute. Henrik Larsson, seemingly surprised the ball had reached him, snatched at his shot and sent the ball wide from 12 yards.

Boavista's strategy was initially unadventurous in the extreme, as if they planned to play out a barren stalemate. Pacheco had restored his principal striker, Elpidio Silva, to the starting line-up after omitting him at Parkhead, but neither the Brazilian nor his foil, Duda, was seen as an attacking force until late in the first half. It was left to Pedrosa, with a 35-yard free-kick that flew high over Rab Douglas's bar, to post their first sign of positive intent after 24 minutes.

Chris Sutton, absent since breaking a wrist against Rangers last month, joined the fray shortly after the half-hour, replacing Paul Lambert, whose right ankle had swollen after an early tackle on Silva. As Celtic adjusted to the loss of their captain, with Sutton taking up an advanced midfield position, Pedro Santos' 20-yard shot veered wide. However, Boavista's unease in the face of the heading prowess of Sutton and Hartson was again evident when Filipe Anunciacão illegally balked the former in the penalty box, only for the referee to wave play on.

A lapse in concentration almost led to Boavista taking a 43rd-minute lead. Joos Valgaeren, who had scored an own goal in the first meeting, was dispossessed by Martelinho, whose centre found Silva outjumping Johan Mjallby. Douglas, despite his lack of activity, made an alert save.

The mediocre quality of Celtic's service to Larsson and Hartson must have provided O'Neill with the text for his half-time talk. He would have reminded his players, too, that they scored at Blackburn, Vigo, Stuttgart and Liverpool. Boavista looked nowhere near as daunting a proposition as Gérard Houllier's side, but the ability to work the flanks, always a Celtic trademark, was conspicuously absent.

It was surprising, then, that Celtic made such a sluggish start to the second half, their passing poor and the reliance on hopeful long balls from the back perhaps betraying tiredness. The lack of atmosphere can not have helped – the stadium is under reconstruction for Euro 2004 and there was a building site behind either goal – but the visitors' bench must have watched with a growing sense of concern.

Pacheco actually contrived to out-fidget O'Neill in the technical area, his agitation increasing as successive Boavista shots went out for throw-ins. But in the 59th minute, Douglas mistimed his leap for a Duda centre and succeeded only in finger-tipping the ball to the unmarked Silva at the far post. The striker had the entire goal to aim at but chose to send the ball straight at the only defender present, Mjallby, who stuck out a knee to divert his header past the upright.

Too often Celtic's front two were isolated from a deep-lying midfield, while Didier Agathé and Alan Thompson tended to operate as wing-backs rather than the wingers for which the situation cried out.

Thompson, a scorer at both Anfield and Stuttgart, at last made an impression with 20 minutes remaining. But his thunderous volley was deflected behind for a corner.

Boavista (4-3-1-2): Ricardo; Martelino, Avalos, Eder, Mario Loja; Filipe Anunciacão, Pedro Santos, Pedrosa (Yuri, 84); Erivan (Jocivalter, 80); Duda, Elpidio Silva (Luiz Claudio, 69). Substitutes not used: Rui Oscar, Bosingwa, Goulart, William (gk).

Celtic (4-4-2): Douglas; Mjallby, Balde, Valgaeren (Smith, 75), Agathé; Petrov, Lennon, Lambert (Sutton, 34), Thompson; Larsson, Hartson. Substitutes not used: Sylla, McNamara, Laursen, Maloney, Marshall (gk).

Referee: V Ivanov (Russia).