Young Boys stunned Tottenham early on to win 3-2 after allowing the English club to recover in the first leg of their Champions League playoff on Tuesday.
The Swiss side led 3-0 within 28 minutes after clinical shots from Senad Lulic, Henri Bienvenu and Xavier Hochstrasser. All three goals came after Spurs' defense was too slow to react to offer goalkeeper Heurelho Gomes any protection.
Spurs center back Sebastian Bassong made amends in the 42nd with a header from a corner.
Young Boys substitute Christian Schneuwly twice came close late on, before Tottenham forward Roman Pavlyuchenko struck in the 82nd to flatter the visitors.
''We played a perfect game for 30 minutes,'' Hochstrasser said. ''But we still have a goal advantage to defend in London.''
The return leg is at White Hart Lane on Aug. 25 with the winner advancing to the lucrative group stage.
Young Boys soon made a mockery of its pre-match status as underdog against a team which broke the Premier League big four clubs' recent monopoly on Champions League places.
The hosts looked sharp, having started their season a month before Tottenham, and comfortable on the artificial grass at Stade de Suisse.
Lulic struck a post in the second minute with a low shot that had Gomes beaten.
The Bosnian midfielder scored in the fourth minute when he reacted first to a loose ball and shot left-footed from eight meters (yards).
Young Boys goalkeeper Marco Woelfli saved well in the seventh, blocking a low shot from Giovani Dan Santos when the Mexico forward ran clear.
It was 2-0 in the 13th when Bienvenu shrugged off Tottenham captain Michael Dawson before the Cameroonian striker placed his shot past Gomes.
The stunned visitors then failed out to cut out Moreno Costanzo's pass, which found Hochstrasser to score with a rising first-time shot.
Tottenham coach Harry Redknapp sent on Tom Huddlestone in the 36th to replace left back Benoit Assou-Ekotto and the sturdy midfielder helped strengthen his side's game.
Six minutes later, Bassong powered a header into the top right corner of the net.
Young Boys regained the initiative early in the second half.
Bienvenu's header just cleared the crossbar in the 68th, and Schneuwly fired over in the 79th and 81st with Tottenham stretched.
Pavlyuchenko has an 80th-minute header saved by Woelfli before scoring a crucial second away goal for Spurs.
The Russia forward collected substitute Robbie Keane's neat pass and fired a shot high past Woelfli at his near post.
Tottenham last played in the European Cup in 1962, when it lost in the semifinals to eventual winner Benfica.
Young Boys last tried to reach the group stage six seasons ago, losing in the qualifying round to Red Star Belgrade. It reached the playoffs by surprising Turkey's Fenerbahce 3-2 on aggregate.
