Besiktas were held to a goalless draw against Sivasspor in the Super Lig, at the 4 Eylul Stadium on Tuesday.
The Black Eagles have now dropped points for the last two rounds of games. Both which have ended in draws.
The Black-Whites are still league leaders but have seen their lead slashed to three points.
Fenerbahce could join Besiktas at the top of table on 72 points if they beat Basaksehir tonight – but they will have played an additional game.
Third-placed Galatasaray meanwhile, can cut the point gap with Besiktas to three points if they beat Trabzonspor tonight – but will also have played an additional game.
Besiktas will face Kayserispor next at the Vodafone Park stadium on Saturday.
There are six games left in the title race so still plenty of time for Fenerbahce and Galatasaray to close the gap with the league leaders.
Besiktas are also in the race for the Turkish Cup after reaching the final. They will face Antalyaspor on 18 May.