Barcelona 0-0 Celtic (agg:0-1)
Rookie goalkeeper David Marshall was the hero as Celtic progressed to the Uefa Cup quarter-finals at the expense of mighty Barcelona.
The 19-year-old made a string of fabulous saves as the Catalan giants pressed to claw back the 1-0 deficit from the first leg at Celtic Park.
Barcelona enjoyed the bulk of possession but could not break down the hard-working Scottish side.
John Kennedy was another Celtic star, making a number of great tackles.
The home side started at a whirlwind pace and Celtic had to withstand a constant barrage of attacks right from the off.
An incisive move involving Carles Puyol and Ronaldinho found Gerard Lopez bursting into the penalty area inside the first minute and Marshall needed to make a great save at the midfielder's feet.
With six minutes gone Henrik Larsson found himself in behind the Barcelona defence but the striker lacked the pace to get away from Puyol.
Marshall then had to smother a header from Gerard, tip over a dangerous cross from Luis Garcia and make a wonderful reflex stop to keep out an awkward close-range attempt from Luis Enrique.
Celtic were finding it hard to hold on to the ball but Neil Lennon, Stilian Petrov and Alan Thompson were beginning to win more tackles in front of their under-pressure defence and disrupt the flow of the home side.
Brazilian ace Ronaldinho was showing lots of neat touches but twice his jinking runs were brought to a shuddering halt by perfectly-timed tackles from Kennedy.
As half-time approached Marshall was able to gather a long range effort from Xavi and Michael Reiziger's blistering shot was deflected wide.
Young David Marshall made some fantastic saves
Didier Agathe made a foray deep into Barcelona territory but delayed his pass, with Larsson and Chris Sutton available, and the chance was gone.
Barcelona could not find the easy rhythm they displayed in the early stages but Celtic were again guilty of giving possession away cheaply.
The home side were laying siege to the Celtic penalty area and Luis Garcia's curling shot drifted narrowly wide of the post.
Larsson was given a glimpse of goal but Victor Valdes held the shot comfortably, while Petrov headed high and wide as Celtic hit on the break.
Ronaldinho had the crowd on their feet with a driving run into the box but Marshall was out quickly to block. The youngster then had to keep out a stinging drive from Gabri.
Marshall then made a breath-taking save to tip over a 10-yard volley from Luis Garcia that looked bound for the top corner of the net.
Barcelona substitute Sergio Garcia headed wide at the back post and saw his 75th minute shot pushed wide by the flying Marshall.
In the final 10 minutes Stanislav Varga and Kennedy made vital interceptions to thwart frantic Barcelona attacks.
Having completed a brilliant victory over one of Europe's elite clubs, Celtic, last season's beaten finalists, now face Spanish side Villareal in the last eight of the competition.
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.
Celtic: Marshall, Kennedy, McNamara (Miller 52), Varga, Agathe, Lennon, Pearson, Petrov, Thompson, Larsson, Sutton (Sylla 83). Subs Not Used: McGovern, Lambert, Mjallby, Beattie, Smith.
Referee: Domenico Messina (Italy).