Gary McAllister wrote himself into Anfield folklore on Thursday after scoring the penalty which sent Liverpool into their first European final for 16 years.

There were just 72 seconds remaining of the first half when the 36-year-old Scot, who won the Merseyside derby on Monday with his late free-kick at Everton, scored from the spot after Patrick Kluivert had handled.

His sweetly-struck spot-kick kept alive the dream of an amazing cup treble with Liverpool marching onto the final in Dortmund on May 16.

There they will face a far less illustrious Spanish club, Alaves, who won their second leg against Kaiserlautern 4-1 to go through 9-2 on aggregate in the other, one-sided semi-final.

The night was full of high emotion. Barcelona oozed class and skill but Liverpool dug deep and found the qualities of old.

Sami Hyypia and Stephane Henchoz shone at the back as the Spanish giants became increasingly desperate and threatened to overpower Liverpool in the second half.

Dietmar Hamann directed midfield and Steven Gerrard, until his exit with 13 minutes remaining, was outstanding.

But this was truly a team performance. In a week which has seen Arsenal and Manchester United fail in Europe, Liverpool took their chance to underline that they are really back in the big time.

Manager Gerard Houllier retained McAllister in the centre of midfield following his outstanding performance at Goodison Park while Gerrard and Michael Owen were restored to the starting line-up.

Vladimir Smicer was asked to provide the attacking invention behind Owen and Emile Heskey, and Robbie Fowler consigned to the bench.

Barcelona, who went out of the same competition at the same stage at Anfield in 1976, sprung a surprise by including ex-Arsenal star Emmanuel Petit in a midfield role.

Michael Reiziger was back after injury so Sergi and Gabri made way from the team left frustrated by the goalless first leg.

Having been pilloried in Spain for their defensive display in the first leg, Liverpool spent more time in Barcelona's half in the opening minutes than they did in the entire 90 minutes in the Nou Camp a fortnight ago.

Liverpool surged forward from the off, but kept giving the ball away as Rivaldo and Patrick Kluivert lurked with intent.

One moment of magic from Rivaldo summed up the task Liverpool faced. He found space 40 yards out and a dipping drive needed a touch from Sander Westerveld to tip it over the bar.

Liverpool's first clear chance came when Smicer played in Owen, who forced the ball past Jose Reina - but, with both men grounded, the ball was hacked away from the goal by Carlos Puyol.

Hyypia sent in a strong, towering header from McAllister's corner but the ball sailed wide after 16 minutes.

A minute later Heskey turned into space on the left and found Smicer eight yards out, his header held by Reina.

Kluivert then tried a cheeky back heel from a Marc Overmars cross, Westerveld diving to his left to save.

Heskey's strength caused Barcelona plenty of problems, but the speed of Barcelona's counter-attacks and the touch and skill of Rivaldo - playing in a floating role - spelt danger every time the Brazilian got near the ball.

Gerrard, playing out on the right again, sent one angled ball for Owen to chase and the little striker almost got on the end of it under pressure from Reiziger.

But Barcelona broke away through Overmars again, and this time he pulled a pass across the box for the unmarked Luis Enrique to drill inches wide of Westerveld's left-hand post after 32 minutes.

Puyol was not enjoying his clashes with Heskey. On two occasions he came off the worst from jarring collisions and hardly endeared himself to the fans by collapsing to the floor.

Rivaldo produced another stunning cameo of skill, beating three men in a matter of yards and nutmegging another before Hyypia powered in to the crash the ball away, sending the Brazilian spinning in the process.

Moments later Gerrard skipped his way into the box where he looked to be clipped by Reiziger, but Swiss referee Urs Meier waved away the protests.

But three minutes later Meier did award a penalty when McAllister's corner was handled by the jumping Kluivert.

McAllister kept his cool in the mayhem which followed to smash the ball past Reina and Liverpool took their precious lead into the half-time break.

Barcelona came out after the break with all guns blazing. They were almost presented with an equaliser by Westerveld, who had been in outstanding form.

The Dutch keeper, who had fluffed a couple of kicked clearances, made a real hash of one after 56 minutes. He sprinted to the edge of his box to try and boot the ball away from Kluivert, who had been played clear by Petit.

But he missed his kick completely and looked back in relief as the ball ran out of play before the striker could catch it.

Barcelona stepped up their pace and intensity. After 58 minutes Simao Pedro came on for Reiziger to play wide on the right, leaving a three-man defence.

Pedro was booked almost immediately for hauling back Smicer in a break down the left.

Houllier's response to Barcelona's tactical change by taking off Owen and pushing substitute Patrik Berger into the problem area where Pedro was operating.

There was more space for Gerrard on the other flank now and he almost got a second goal on 65 minutes when Hamann's instant pass sent him away on the right. The young England star drilled a low shot inches wide of the far post.

But the pressure was continuing to mount on Liverpool.

Kluivert saw a flicked header go just over from Pedro's cross before the visitors threw on another attacker in Dani Garcia for Overmars, who had been handled well by Markus Babbel.

Danny Murphy was next into the fray, taking over from a tiring Gerrard, who had only been passed fit just before the start.

Robbie Fowler took over from Smicer with just 10 tension-packed minutes left.

Westerveld was booked after 86 minutes for time-wasting while taking a free-kick.

Four minutes of injury-time added to the agony for the Kop, but referee Meier finally brought the agony to an end with the final whistle.

Teams:

Liverpool: Westerveld, Babbel, Henchoz, Hyypia, Carragher, Gerrard (Murphy 78), Hamann, McAllister, Smicer (Fowler 80), Heskey, Owen (Berger 63).

Subs Not Used: Arphexad, Ziege, Vignal, Wright.

Booked: Westerveld.

Goals: McAllister 45 pen.

Barcelona: Reina, Reiziger (Simao 59), de Boer, Puyol, Petit, Luis Enrique, Cocu, Guardiola , Overmars (Dani 74), Rivaldo,Kluivert.

Subs Not Used: Dutruel, De la Pena, Xavi, Gabri, Zenden.

Booked: Simao.

Agg (1-0)

Att: 44,203

Ref: Urs Meier (Switzerland).