McLaren's Lewis Hamilton was fastest on Saturday in the third and final practice for the Chinese Grand Prix, edging out team-mate and fellow Briton Jenson Button.
Hamilton, whose highest possible grid position for Sunday's race is sixth after he incurred a penalty for a gearbox change, set the best time of the week when he clocked 1min 35.940sec in the last five minutes. ( See our RACECENTRE for timings and the latest from Shanghai)
The 2008 world champion also posted the quickest time in the first practice.
Button was 0.123sec behind Hamilton, with the Mercedes pairing of Nico Rosberg and Michael Schumacher, who set the fastest time on Friday, the next quickest.
Mark Webber, in a Red Bull, was fifth-fastest, more than half a second shy of Hamilton, followed by Williams's Pastor Maldonado.
Reigning two-time world champion Sebastian Vettel was down in ninth, a second off the top time, while championship leader Fernando Alonso could only muster the 15th-fastest mark.