Teenage goalkeeper David Marshall produced a stunning display in the Nou Camp as Celtic enjoyed one of their greatest European nights.

The Glasgow side clung onto a 1-0 lead from Parkhead to book their place in the quarter-final of the UEFA Cup, and a tie with Villareal, thanks in the main to the heroics of the 19-year-old goalkeeper.

It was an incredible answer to those who doubted that the youngster and Celtic's walking wounded would be up for the challenge.

Manager Martin O'Neill took a gamble with Chris Sutton, Alan Thompson, Stanislav Varga and Didier Agathe all declaring themselves fit to play but that paid off.

Marshall was given an unnecessary test after just 20 seconds when skipper Jackie McNamara's mis-hit backpass had the goalkeeper stretching to keep the ball from going for a corner.

But a minute later the rookie keeper produced a brilliant save to prevent Barcelona from scoring which would have done his nerves the world of good.

Puyol did brilliantly to cut in from the right touchline before finding Ronaldinho. The Brazilian threaded Gerard through on goal and he would have scored but Marshall raced off his line to flick the ball away from his feet.

Celtic then had a great chance to get a vital away goal when Sutton played Henrik Larsson through on goal but he could not find the pace to get away and Puyol made a great tackle.

The visitors almost paid the price for missing that chance when Barcelona went close to scoring again in the ninth minute.

Ronaldinho picked out Gerard again but his header from eight yards out was again superbly saved by Marshall to his right.

The youngster again had to be alert moments later to tip Garcia's dipping long-range effort over the crossbar.

But Marshall bettered even that in the 13th minute when Ronaldinho flicked on Xavi's corner to Luis Enrique at the back post but Marshall pushed away his header with a fantastic reaction save to come to his side's rescue again.

Ronaldinho was running the show but Italian referee Domenico Messina was not interested in his laughable claims for a penalty after 21 minutes. The South American ran at the Celtic defence menacingly but a well-timed challenge from Scotland Under-21 defender John Kennedy saved his side.

The World Cup winner was at his best again, two minutes later, when he ghosted past Didier Agathe and cut the ball back to Luis Garcia but Varga made a desperate block to deny him.

Celtic were given a lift though in the 34th minute when Puyol limped off and Frank Rijkaard brought on Rafael Marquez.

They finally tested Victor Valdes moments later when he looked as if he might fumble Larsson's long-range snapshot but he hung onto the ball with Thompson pouncing.

The Englishman was then in the wars to give his manager some concern five minutes before the break after being caught late by Ronaldinho but he soldiered on.

Marshall was again called into action in the final minute of the half to save Xavi's dipping and awkward long-range strike.

He would have not got near Michael Reiziger's late strike, after good work from Ronaldinho and Luis Garcia, but fortunately for Celtic it flew past the upright.

McNamara was quickly hurt after the restart when he needed treatment after appearing to collide with Kennedy as they went in for a challenge with Garcia. The Scot was obviously in some distress and he was replaced by Manchester United-bound Miller in the 50th minute.

Barcelona started to get jittery and Ronaldinho was becoming more ineffective as the clock ticked down. But they still threatened and Garcia curled a superb left-footed effort just past the post in the 58th minute after being picked out on the right flank by Gabri.

Celtic knew they would could get chances the longer the game went on and Larsson should have done better again in the 62nd minute.

Petrov burst forward into the area but he checked back and curled a harmless left-footed effort into the hands of Valdes.

Rijkaard made another change in the 64th minute by bringing on Sergio Garcia for Enrique before Petrov headed Agathe's cross high into the crowd.

Having been quiet for a while Ronaldinho sprung to life again in the 67th minute when he flew into the area and only a block from Marshall near the touchline stopped him.

Moments later he teed the ball up for Gabri but his shot was stopped again by the inspired youngster.

Marshall pulled out another incredible point-blank save in the 70th minute when he tipped Garcia's volley, from Xavi's cross, over the crossbar.

The pressure was relentless from the home side and Sergio Garcia headed wide from Gabri's cross in the 73rd minute.

But Marshall was refusing to give up to his side's lead and he denied Garcia again moments later when he flung himself to his left to turn the ball around the post.

The Barcelona bench, and in particularly Puyol were animated at the side of the pitch as Celtic continued to frustrate them before the final whistle arrived to put the travelling fans out of their misery and spark emotional scenes in the Nou Camp and in Glasgow.

Teams

Barcelona Valdes, Reiziger (Overmars 53), Puyol (Marquez 34), Oleguer, Xavi, Cocu, Gerard, Gabri, Luis Enrique (Sergio 64), Ronaldinho, Luis Garcia.

Subs Not Used: Rustu, Quaresma, Iniesta, Oscar Lopez.

Booked: Ronaldinho.

Celtic Marshall, Kennedy, McNamara (Miller 52), Varga, Agathe, Lennon, Pearson, Petrov, Thompson, Larsson, Sutton (Sylla 83).

Subs Not Used: McGovern, Lambert, Mjallby, Beattie, Smith.

Booked: Petrov.

Agg (0-1) Att: 78,000

Ref: Domenico Messina (Italy).