A Bafetimbi Gomis-led Galatasaray topped the Turkish Spor Toto Super Lig on Sunday after a 2-1 home win against Istanbulspor.
Veteran French forward Gomis scored two headers in the first half at Nef Stadium.
The visitors narrowed the gap to one after Turkish defender Mehmet Yesil's header beat Galatasaray goalkeeper Okan Kocuk in the 82nd minute.
Near the end of the match, Istanbulspor's Emir Kaan Gultekin missed a chance in a one-on-one as Galatasaray barely won the match.
In 14 matches, leaders Galatasaray have 30 points to oust archrivals Fenerbahce, who have 29 points.
Fenerbahce moved down to second spot after Galatasaray's win.
Istanbulspor are still in the relegation zone with eight points.
Earlier Sunday, Besiktas drew with Gaziantep FK 1-1 in an away match.
Seventh-place Besiktas have 23 points in the league table.
Mid-table Gaziantep FK collected 17 points.
