By Alan Baldwin
SAO PAULO (Reuters) - Nico Rosberg completed a Brazilian Grand Prix practice hat-trick on Saturday by lapping faster than Mercedes team mate and championship leader Lewis Hamilton in the third and final session.
Rosberg was fastest in both Friday sessions, with Hamilton second, and the order on the timesheets was unchanged at a cloudy but dry Interlagos as drivers put in their last laps before qualifying.
The German's best of one minute 10.446 seconds on soft tires was 0.114 faster than Hamilton's, with the two Williams of Brazilian Felipe Massa and Finland's Valtteri Bottas third and fourth on a dominant morning for Mercedes-powered cars.
Hamilton leads Rosberg by 24 points with two races remaining, but 75 points still to be won due to double being awarded in the Abu Dhabi finale.
Rosberg will be chasing his 10th pole of the season in qualifying but Hamilton has won the last five grands prix and has 10 wins to the German's four for the year.
Australian Daniel Ricciardo was fifth fastest for Red Bull with McLaren's Jenson Button sixth and finally getting up to speed after a troubled Friday.
The two Ferraris of Kimi Raikkonen and Fernando Alonso lapped seventh and eighth fastest in a field of just 18 cars due to the absence of Caterham and now-defunct Marussia.
(Reporting by Alan Baldwin, editing by Rex Gowar)