After defeats by Ferencvaros and Benfica in their first two league phase fixtures, Martin O’Neill’s side struggled to impose themselves on the visitors who were neat and tidy without really testing Hoops keeper Sam Johnstone.

Germany midfielder Mika Baur fired the home side in front just over a minute into the second half to thrill the Celtic fans but Spain defender Javi Rodriguez scored twice in three minutes – a header then an unstoppable drive – to stun the home side who could not find a way back.

It was another damaging Euro night for the Scottish champions, knocked out of the Champions League qualifiers by LASK on a 5-4 aggregate after being 4-0 up at one stage earlier in the season.

Celtic, four points clear of Old Firm rivals Rangers at the top of the William Hill Premiership, face Hibernian at Easter Road on Sunday but while they continue to thrive domestically, European football remains a tougher terrain.