The coach of the Turkish club Trabzonspor, Abdullah Avci, on Tuesday announced his resignation after a lacklustre spell despite leading his team to the Super Lig last season.
"The time has come to bid farewell to Trabzonspor, which I love so much, and to the beautiful people of this beautiful city," he said on Twitter.
Trabzonspor won the title last season after a 38-year wait but have lost three of their last four matches in the Super Lig.
They are in sixth place in the table, 19 points behind leaders Galatasaray.
They failed to reach the group stage of the Champions League losing 2-1 on aggregate to Copenhagen in August.
Last month, they lost 2-1 over two legs to Basle in the Europa Conference League play-off round.
Trabzonspor's president Ahmet Agaoglu resigned last week.