Substitute Hakan Yakin returned to haunt the Scottish champions five years after he helped Basle knock them out in the qualifying rounds for the Champions League, hitting two late goals tonight to give the scoreline an emphatic look.

Celtic did not perform near the standard they displayed two nights ago against Basle and were deservedly beaten, with only Jiri Jarosik's first-half goal to show for their efforts.

Young Boys first threatened the Celtic goal in the 12th minute when 'keeper Michael McGovern deserted his line and was almost punished by Joao Paolo. Fortunately for McGovern, the Brazilian striker failed to produce a composed finish from close range.

The visitors to Switzerland were unable to find any rhythm in the early stages and Young Boys deserved their opening goal in the 25th minute, a header by Brazilian defender Tiago from a left-sided corner Celtic failed to deal with.

Joao Paulo then shocked the whole Celtic defence in the 29th minute when he appeared all alone in front of McGovern after a blocked shot from distance, but the Celtic goalkeeper did superbly well to save for a corner.

Celtic had their first chance in the 35th minute when Balde reached a free-kick from the left side by Lee Naylor but headed over Marco Wolfli's crossbar.

Ivory Coast international Gilles Yapi then missed by just inches with a stunning 20-yard shot, and Young Boys' dominance was threatening to bring a second goal.

The next goal went to Celtic however, when Naylor's long throw-in found Jan Vennegoor of Hesselink who headed the ball on to Jarosik and the chance from eight yards was calmly put away by the former Chelsea player.

Young Boys regained their lead only two minutes after the break when Marco Schneuwly escaped the attention of the Celtic defenders and volleyed home a left-wing cross from close range.

Maciej Zurawski should have hauled Celtic level again in the 55th minute after connecting with a stunning pass by McGeady, but with the goal beckoning the Pole failed to apply a clinical finish.

Celtic were showing signs of improvement however and McGeady, a half-time replacement for Jarosik, was doing the damage from the left flank.

Gordon Strachan surprised many observers when he withdrew injured substitute Steven Pressley and replaced him with Evander Sno. Sno himself had been replaced at half-time and his second run-out lasted just a short while before Chris Killen took his place.

While Celtic pushed for an equaliser, they were finding Young Boys substitute Erhan Kavak hard to contain on the left of the Swiss side's midfield. He repeatedly tormented Teddy Bjarnason and came close to scoring with a spectacular volley after 80 minutes.

Young Boys substitute Franck Madou had a big chance just after coming on when he rushed his shot from eight yards and missed the target.

Celtic, who would have been crowned UhrenCup champions with a victory, fell 3-1 behind in the 88th minute when Yakin tucked away Madou's pass after a swift counter-attack.

Yakin, who came on after 75 minutes, added his second and the Berne side's fourth goal in the 90th minute as the scoreline failed to reflect Celtic's second-half improvement.

Despite the result, there were encouraging aspects to Celtic's performance, notably the centre midfield partnership between new signing Massimo Donati and last season's expensive mis-fit Thomas Gravesen. Strachan wants both to play key roles in the coming season and they looked to have a decent understanding.