Barcelona - Nico Rosberg dominated another Formula One practice on Friday in a strong showing of the Williams team as a return to the established order was yet to materialize at the Spanish Grand Prix.

The German Rosberg clocked the day's fastest time of 1 minute 21.588 seconds on the 4.655-kilometres Circuit de Catalunya in a light car with little fuel. Team-mate Kazuki Nakajima of Japan came second in 1:21.740 minutes.

Ex-champion Fernando Alonso of Spain was third in a Williams in 1:21.781 while championship leader Jenson Button placed sixth in 1:22.052 in a Brawn GP after topping the morning session with a slower time than Rosberg's afternoon result.

Button, a three time winner from Australia, Malaysia and Bahrain, leads with 31 points from his team-mate Rubens Barrichello (19) and Red Bull's German driver Sebastian Vettel (18), who won the other race in China.

The big three of McLaren, Ferrari and BMW have had a poor start into the campaign dominated by Brawn, Toyota and Red Bull, but hope to rebound with improved cars now that the season has come to Europe for the next nine races.

"The beginning of the European Formula One season in Barcelona will be a true test for the future balance of power," said Mercedes motorsport chief Norbert Haug in the buildup.

However, the best on Feriday afternoon training was Ferrari's Kimi Raikkonen in 10th place. World champion Lewis Hamilton was 13th for McLaren while BMW riders Robert Kubica and Nick Heidfeld trailed yet again in 16th and 17th place, respectively, after fast morning times.

Qualifying is scheduled for Saturday and the first European race of the season on Sunday.

Inbetween Friday's sessions Hamilton was honored with a plaque on the circuit's "Walk of Champions" alongside Ayrton Senna and Michael Schumacher after becoming the youngest world champion last year at age 23.

"Knowing I am welcome here is a great thing for me," said Hamilton, who was the target of racist abuse from fans in Barcelona during pre-season testing in 2008.

"To be recognized as world champion is something very, very special to me," he said.