4. Utrecht 4-0 Celtic (August 2010)
Celtic took a convincing 2-0 lead to the Netherlands in their 2010 Europa league qualifier with Utrecht and had virtually sealed their passage into the group stages, or so they might have thought. After 20 minutes of the second leg, profligate striker Ricky Van Wolfswinkel had put the Dutch side level on aggregate with two penalties. An almighty collapse saw Celtic destroyed in brutal fashion. Van Wolfswinkel grabbed his third (more than he has ever scored for Norwich) with a sweet curling effort, before Dutch Irish sensation Barry Maguire piled on the misery with a rasping drive. Neil Lennon's side surrendered a huge advantage in incredible style and the match truly ranks as one of the worst European performances in Celtic's illustrious history. An away goal would have given them some hope, but that was never likely going to come through the strikeforce of Giorgios Samaras and the impotent Marc-Antoine Fortuné.