Yigit Incedemir scored a sixth minute goal to put the home side ahead and the relegation battling side were able to hang on for the remainder of the game to record a valuable three points.
A victory would have took the Istanbul minnows into joint fourth place alongside Basaksehir on 40 points but they were unable to make up lost ground.
On-loan Chelsea defender Kenneth Omeruo will start for Kasimpasa and put on a decent display making the highest number of interceptions (3) and the most tackles in defence (3).
The Nigerian international was also strong in the air making a total of five clearances but the Istanbul based side struggled going forwards and were unable to find the back of the net.
MEDICANA SİVASSPOR – KASIMPAŞA
Stadium: 4 Eylül
Referee: Yaşar Kemal Uğurlu
Kick-Off: 17:00 gMT
Confirmed Starting Line-ups
Sivasspor: Korcan Çelikay (min. 46 Setkus), Cicinho, Boye, Oumari, Ziya Erdal, Yiğit İncedemir, Adem Koçak, Tanase (min. 77 Hasan Kabze), Beykan Şimşek (min. 83 Hussain), Chahechouhe, Texeira
Manager: Mesut Bakkal
Kasimpasa: Isaksson, Veysel Sarı, Omeruo, Titi, Bozhikov, Abdullah Durak, Castro (min. 75 Hakan Arslan), Tunay Torun, Ferhat Kiraz (min. 46 Del Valle) , Scarione, Malki (min. 46 Adem Büyük)
Manager: Rıza Çalımbay
Goal: min. 6 Yiğit İncedemir (Medicana Sivasspor)
Yellow Cards: min. 40 Ferhat Kiraz (Kasımpaşa), min. 50 Boye, min. 87 Adem Koçak (Medicana Sivasspor)