A converted penalty from Felipe Melo was enough for Galatasaray to record a 1-0 victory over Porto in the opening match of the Emirates Cup.
It proved to be a frustrating encounter for the Portuguese side, who saw a penalty of their own from Jackson Martinez saved by Fernando Muslera in the 18th minute.
Then, after Melo had scored from the spot 19 minutes from time, they missed another spot kick from 12 yards. On this occasion it was Lucho Gonzalez who failed to hit the target in the 77th minute.
Paulo Fonseca's side continued to push forward in the closing stages to try to secure an equalising goal, but the Galatasaray rearguard held firm.
The other two teams in the competition, Arsenal and Napoli, will face each other later today.