Celtic's progress in the Champions League has been delayed following a 2-1 defeat to Benfica in Lisbon.
Benfica started brightly and were ahead in the sixth minute when Ola John took advantage of some sloppy Celtic defending to fire a low shot past a helpless Fraser Forster.
Despite the hosts dominating possession for the majority of the first half, Celtic did manage to find an equaliser in the 31st minute.
Charlie Mulgrew delivered a corner to the back post and Georgios Samaras was left unmarked to level the scores in Lisbon with a close-range header.
Benfica once again took control of the match after the break and Celtic were left thanking Adam Matthews after the full-back cleared Rodrigo Lima's drilled effort off the line.
Neil Lennon's side continued to live dangerously and were once again fortunate to remain on level terms when Luisao somehow managed to scoop the ball over the crossbar from eight yards out.
Celtic's resistance was finally broken with 20 minutes remaining as Luisao was allowed to find Ezequiel Garay, who volleyed past Forster to give his side the lead.
Benfica were close to adding a third moments later when Eduardo Salvio rattled the crossbar with a powerful effort from 30 yards out.
The hosts continued to create chances in the closing stages but Forster was alert to keep out Oscar Cardozo to reduce the size of his team's defeat.
