Bursaspor's Onuralp Bitim and Andrew Andrews made a double-double at Belgrade's Stark Arena.
Bitim scored 20 points and 10 rebounds while Andrews produced 24 points and 10 assists in the winning effort.
John Holland finished with 17 points.
Aleksa Avramovic netted 23 points and Mathias Lessort 20 points and eight rebounds for Zeljko Obradovic's side, which suffered their first home loss of the season.
Bursaspor made club history by grabbing a quarterfinal place where it will play Cedevita Olimpija Ljubljana from Slovenia.