Giresunspor defeated The Lions with Magomed Suleymanov's early goal in the 11th minute.
The Yellow Reds managed to win only one game in their last nine Turkish Super Lig matches.
Galatasaray are 10th with 27 points -- 22 points behind leaders Trabzonspor -- while Giresunspor are placed 13th with 25 points in the Super Lig standings.
SATURDAY'S RESULTS:
Gaziantep FK-VavaCars Fatih Karagumruk: 3-1
Aytemiz Alanyaspor-Medipol Basaksehir: 1-1
Kasimpasa-Atakas Hatayspor: 3-1
Galatasaray-GZT Giresunspor: 0-1
