Sakhir, Bahrain - Nico Rosberg returned to the top of the timesheets on Friday when he dominated practice for the Bahrain Formula One Grand Prix in a Williams. The big three of McLaren-Mercedes, Ferrari and BMW Sauber, by contrast, trailed with five of their six drivers at the rear of the field placed 16th to 20th after world champion Lewis Hamilton had led the morning session for McLaren.
Rosberg posted 1 minute 33.339 for the 5.412-kilometres lap on the Bahrain International Circuit.
The German topped several training sessions at the previous races in Australia, Malaysia and China, and extensive pre-season testing in Bahrain seemingly also paid off.
"We have a good car and can play a strong role in the race," said Rosberg.
Former champion Fernando Alonso was second in a Renault in 1:33.530 and Jarno Trulli was third in a Toyota in 1:33.616 minutes.
Sunday's China GP winner Sebastian Vettel of Germany was fourth in a Red Bull and British season leader Jenson Button sixth for Brawn GP.
Button leads the championship from two wins and one third place with 21 points from Brazilian team-mate Rubens Barrichello (15). Vettel and compatriot Timo Glock (Toyota) have 10 points each.
Brawn, Toyota and Williams use a double diffuser which was declared legal by the ruling body FIA and seemingly still gives them an advantage although Renault and Red Bull are competitive as well.
But the top teams are yet to catch up in a difficult season for them.
Hamilton was their best in 11th place in 1:33.994 a few hours after leading the morning session in 1:33.647 from the BMW duo of Nick Heidfeld and Robert Kubica.
The 2007 and 2008 Bahrain winner Felipe Massa was 16th in a Ferrari after coming eighth in the morning, Kubica 17th, Kimi Raikkonen 18th in the other Ferrari, Heikki Kovalainen 19th in the second McLaren and Heidfeld last in 20th place.
But for Mercedes motorsport chief Norbert Haug the result wasn't all doom and gloom. Haug said his cars carried a lot of fuel and he set high hopes in the power-boosting KERS system which only McLaren-Mercedes have used in every race this season.
"It doesn't look that bad. We need a good qualifying and reliability. The KERS is important here, we are the only ones who have used it in every race," said Haug.
McLaren have just eight points from the first three races, BMW are on four and Ferrari have zero from the first three races.
A third practice session and qualifying are scheduled for Saturday and the 57-lap race on Sunday.
