Ankaragucu's Argentine midfielder Oscar Scarione scored the winning goal from the penalty spot in the 62nd minute at Eryaman Stadium.
So, Galatasaray was unable to win for eight matches in the league. The Lions, who have already thrown in the towel, got their last win on March 1 by 3-0 against Genclerbirligi.
They were one of the title contenders in the league at the time. But after that win, Galatasaray had four draws and four losses.
Galatasaray had 52 points in 32 games to be in the fifth spot in standings.
Despite the win, Ankaragucu were still in last place with 29 points.