McLaren's Lewis Hamilton set down a marker for the weekend with the quickest time of the first two practice sessions for the Chinese Grand Prix on Friday.
The former world champion, who finished sixth in the last two races, swept around the 5.451 kilometre circuit in one minute 35.217 seconds on a cool but sunny day in Shanghai. German Nico Rosberg was second fastest for Mercedes, 0.248 seconds behind Hamilton but ahead of the Briton's team-mate and reigning world champion Jenson Button.
Michael Schumacher completed the dominance of the Mercedes-powered cars with the fourth fastest lap ahead of the Red Bull duo of Sebastian Vettel and Mark Webber, who finished one-two in the last race in Malaysia and in China last year.
Adrian Sutil made it four Germans in the top seven cars with another impressive day for Force India, brushing off a stewards' reprimand for not reducing his speed sufficiently when yellow flags were displayed.
The largely uneventful second session followed a dramatic morning when Fernando Alonso's Ferrari came to a halt in flames and Toro Rosso's Sebastien Buemi survived a spectacular crash unscathed.
Twice world champion Alonso failed to finish the last race in Malaysia because of an engine failure and he and Ferrari had been talking down concerns over endemic problems ever since.
After nearly an hour of the first of Friday's two sessions, however, the Spaniard's car drew to a halt at the side of the track on turn six with smoke and flames coming from the rear.
Alonso did not spend long in the car before jumping out, flipping off his helmet and making his way back to the pit lane, returning to the track in the afternoon with a new engine to set the 10th fastest time.
Buemi came safely through a more spectacular incident late in the first session when the front wheels exploded off his Toro Rosso at the end of the main straight, both tyres clearing the safety fence as the Swiss came to a halt in the gravel.
The session was red flagged and there was a 10 minute break before the last five minutes were completed, but nobody was able to better Button's best time of one minute 36.677 seconds.Buemi failed to return for the afternoon session as team mechanics worked on his car.