F1 reigning champion Lewis Hamilton seemed back on track on his McLaren's MP4-24 car with a changed "double-decker" diffuser on Friday to race fastest lap in the Chinese Grand Prix.

The Briton shrugged off the dismay perjury in the season opener Australian GP to clock 1:37.334 thanks to McLaren's swift diffuser upgrading, marking a encouraging fastest lap ahead of his compatriot Jenson Button and Rubens Barrichello, who're both from the season thriller Brawn GP.

Button was 0.116 seconds trailing Hamilton's best, but still regarded as a favorite for the pole position and the top podium finisher.

F1 rookie team Brawn GP is poised for a stunning constructors' trophy if the outfit can prolong its sweep force like the first two Grands Prix.

McLaren's newly-updated diffuser proved to be working as Hamilton's teammate Heikki Kovalainen also recorded a remarkable fourth best in the first practice session in 1:37.672.

Australia's Mark Webber pulled off a fifth finish for Red Bull, which was the best result from the conventional diffuser teams.

Traditional powerhouse Ferrari remained uncompetitive with two drivers Kimi Raikkonen and Felipe Massa ranking in lowly 11th and 15th.

(Xinhua News Agency April 17, 2009)