Red Bull Racing's Mark Webber used Bridgestone's soft compound Potenza to make it three poles in the last three races after setting a 1min 26.295secs lap around Istanbul Park.
Webber will be joined on the front row for Sunday's Turkish Grand Prix by Vodafone McLaren Mercedes
driver Lewis Hamilton. The morning practice session saw Webber's team-mate Sebastian Vettel go fastest, using the soft compound for a 1min 27.086secs.
Q&A with Hirohide Hamashima - Bridgestone Director of Motorsport Tyre Development
What was significant about today's running?
"This morning was certainly cooler than yesterday which affected grip levels from the tyres. However, by the afternoon the temperature was much warmer. The changing temperatures made finding the best set-up even more difficult for the teams at this venue where this is already a challenge due to the track surface evolution over the weekend. The difficult to judge grip levels meant that many people found the limit as they danced on the edge of adhesion today. Mark Webber proved the best at this when it mattered most, so congratulations to him for his third pole in a row."
What are the tyre strategy considerations for tomorrow's race?
"Track surface evolution will continue to be a factor tomorrow so judging when which tyre compound will deliver the best performance during the course of the race will be tough. The difference between the soft and the hard compound is difficult to tell here as they are very close, and the track conditions and temperatures have been changing. This is a big challenge for teams and drivers. Our microscopic analysis of yesterday's tyres did not highlight anything untoward, however teams and Bridgestone will remain vigilant as we face Turn Eight for the 58 laps of tomorrow's race."