Ten-man Debrecen's Europa League Group I campaign got off to an awful start as they were hammered 5-0 at home by Ukrainian opponents Metalist Kharkiv.
Edmar had opened the scoring for the visitors before Cleiton Xavier added a second and the hosts had Peter Kabat dismissed for violent conduct just before the interval.
Further goals followed for Edmar, Fininho and Sergey Valyaev to cap a miserable night for the Hungarians.
Cleiton had gone close with an effort from long range before the visitors took the lead in the 24th minute.
Freda Taison crossed from the left and Edmar coolly slotted home from 12 yards.
Debrecen sought a rapid equaliser and Peter Kabat was unlucky not to level as his shot came back off the post.
But things soon got worse for the hosts as Metalist doubled their lead.
Cleiton picked up the ball on the edge of the area in the 34th minute and curled a low shot beyond Debrecen keeper Mindaugas Malinauskas.
And the Hungarian side's task became almost impossible when Kabat saw red just two minutes before the break.
Taison went close to adding a third for the visitors after the interval but dragged his effort wide while Peter Czvitkovics saw a speculative effort saved by Vladimir Disljenkovic at the other end.
Metalist were in complete control but it took them until the 74th minute to extend their lead further.
Cleiton produced an inswinging corner from the left and Edmar was left with the simple task of prodding the ball home from close range.
It quickly became four just three minutes later with Cleiton once again creating the opportunity for Fininho to blast a left-footed shot into the top corner.
Adam Komlosi had a chance to pull a goal back for the home side but his header from Czvitkovics' cross was clawed away by Disljenkovic.
And Debrecen's misery was complete as Sergey Valyaev tucked home Vitali Bordiyan's cross in the final minute of normal time.