Burnley will need a rousing comeback next week after suffering a 3-1 away defeat to Olympiakos in the first leg of their Europa League playoff on Thursday.
Burnley finished the game with 10 men after Ben Gibson received a second yellow card for handling in the 59th minute.
Konstantinos Fortounis opened the scoring after 19 minutes before Chris Wood equalised via a penalty just after the half-hour mark.
Andreas Bouchalakis gave the hosts the lead in the 48th minute before Gibson's handball gifted Olympiakos a penalty of their own which Fortounis converted to complete his brace.
The two will next meet each other next Thursday in England, with Sean Dyche's side needing a big result to continue their first European odyssey since the 1966-67 season.