
The Finn registered a time of 1 minute 27.988 seconds for the 5.338-kilometre Istanbul Park circuit followed by team-mate Felipe Massa in 1:28.391.
Defending world champion Fernando Alonso was third in a McLaren- Mercedes followed by team-mate and championship leader Lewis Hamilton.
Renault's Heikki Kovalainen was fifth fastest with Nico Rosberg sixth in a Williams.
Hamilton heads the drivers' standings on 80 points with six races remaining, seven clear of Alonso in second. Raikkonen lies third on 60 points, one ahead of Massa.
DPA