Galatasaray went 3-0 up within 30 minutes against Bursaspor on Sunday afternoon.
The second was a real beauty, scored by former Inter man Wesley Sneijder.
The Dutch midfielder unleashed a banging left foot shot which found the top corner, with the diving keeper getting no way near.
Chelsea may pinpoint Sneijder as the key player in the Champions League last 16 game.
Sneijder had a hat trick by half time as the sides went in at 4-0.