Ferrari's Felipe Massa set a blistering pace to top the timesheets at the end of Chinese Grand Prix practice after Nico Rosberg had led a Mercedes one-two in the morning session.
Kimi Raikkonen, winner of Formula One's Melbourne season-opener in March, was second fastest for Lotus at the circuit outside Shanghai.
Red Bull's Mark Webber, whose working relationship with world champion Sebastian Vettel hit a new low after a team orders storm in Malaysia, ended both sessions ahead of the German.
