Goals from Victor Wanyama and UEFA Champions League debutant Tony Watt earned Celtic FC a memorable victory against FC Barcelona, a day after the Scottish club's 125th anniversary.
Wanyama powered in a header from a corner in the first half, and Neil Lennon's men were forced to soak up a huge amount of pressure as Barcelona pushed. The visitors hit the woodwork twice before the 18-year-old Watt slid in a second to seal it for Celtic, despite Lionel Messi's added-time reply.
Already deprived of the services of Gary Hooper, Emilio Izaguirre and James Forrest, Celtic suffered another pre-match blow with the news that captain Scott Brown had succumbed to a virus. However, the Hoops made light of their casualty list by storming into the lead on 21 minutes.
Set pieces were always going to be important if Celtic were to get the better of a Barcelona side who have been vulnerable to an aerial threat in recent weeks; so it proved. From their first corner, Charlie Mulgrew swung a high ball to the back post where Wanyama rose highest to head powerfully past Víctor Valdés.
The Blaugrana are not the kind of team to panic – as they proved at the Camp Nou a fortnight ago – and they immediately went in search of an equaliser. First Messi and Andrés Iniesta worked a one-two on the edge of the area before the Argentinian hit a deflected shot which Fraser Forster tipped onto the crossbar. Moments later Alexis Sánchez beat the goalkeeper with a header that bounced off the base of the post.
Tito Vilanova's side resumed their offensive after the break with Daniel Alves a constant danger down the right. His personal contest with Adam Matthews, playing in an unaccustomed left-back role, was becoming a key feature of the game. More familiar was the performance of Forster. The Englishman excelled in the corresponding fixture and once again he came to his team's rescue on the hour, blocking an Alexis shot.
With 20 minutes remaining it looked as though Celtic's defensive wall had been breached. Messi's curling shot seemed destined for the bottom corner until Forster stuck out a hand to claw the ball to safety. Then, with seven minutes left, Celtic Park was sent into raptures as Watt capitalised when Xavi Hernández misjudged the bounce of a long clearance, racing through and slotting past Valdés.
As the match entered added time Messi pulled a goal back, pouncing on a loose ball after another great Forster save. It was too little, too late for Barcelona though; nobody could deny the Glasgow club their belated birthday surprise.