Ahmed Mahgoub opened the scoring in the 21st minute.
Yusuf Ozdemir made it 2-0 in the 36th minute but Karimi pulled a goal back in the 59th minute.
Efecan Karaca scored Alanyaspor’s third goal from the penalty spot in the 72nd minute.
Kayserispor sits 15th in the Super Lig table with 23 points, nine points adrift of leader Fenerbahce.