Wesley Sneijder took centre stage to keep Galatasaray on course for the Super Lig title with the only goal in its 1-0 win over Genclerbirligi.
Gala made it five league wins in a row against the mid-table outfit thanks to Sneijder's low shot from the edge of the area, but Ferhat Kaplan's poor attempt to save his effort caused controversy in Turkey.
Some of the league leader's rivals questioned the 26-year-old for pulling out of a dive when he looked able to save Sneijder's effort, and even resulted in accusations of match-fixing aimed at the Genclerbirligi goalkeeper.
Fenerbahce remains three points behind its fierce rival thanks to a 1-0 win over 10-man Mersin Idmanyurdu, but needed a last-minute goal from Emre Belozoglu to earn all three points.
With two matches of the season remaining the title fight could go right to the wire, but Besiktas is out of the hunt after being beaten 1-0 by Konyaspor - Gabriel Torje with the decisive goal.
The battle to stay in the division is over after Rizespor recorded back-to-back victories with a 3-1 triumph over Akhisar Belediyespor.
Goals from Leonard Kweuke, Deniz Kadah and Sercan Kaya preserved Rizespor's place in the top flight and condemned Karabükspor and Balıkesirspor to the drop.
Kayseri Erciyesspor's relegation had been confirmed before the Rizespor victory after its 1-0 defeat to Istanbul Basaksehir, but the fate of Karabukspor and Balikesirspor was not decided until Monday.
Balikesirspor must have thought it had done enough to keep its hopes alive after a 4-2 win over Karabukspor, but Rizespor's win means it can no longer be caught.
Gaziantepspor saw its winless run extended to seven matches with a 2-0 defeat to Bursaspor - Aziz Behich coming on with 25 minutes remaining for Bursaspor - Eskisehirspor beat Trabzonspor 2-0 and Sivasspor secured its place in the division with a 1-1 draw against Kasimpasa.
Meanwhile, Osmanlispor joined Kayserispor in earning promotion to the Super Lig next season.