Lewis Hamilton replaced McLaren team-mate Jenson Button at the head of the free practice times at the end of the opening day at Shanghai International Circuit, as Mercedes power dominated proceedings.
Although every driver who took part in the second 90-minute session ahead of Sunday's Chinese Grand Prix improved on his time - the only exceptions were Paul di Resta and Sebastien Buemi, who sat out - no-one could deny the two McLaren and two Mercedes drivers a place in the top four, as Button and Hamilton swapped places and Nico Rosberg and Michael Schumacher held firm in second and fourth respectively. All four drivers broke into the 1min 35s in the afternoon session, with only the two Red Bull cars able to join them, Sebastien Vettel ahead of Mark Webber in fifth and sixth.
Adrian Sutil, Jaime Alguersuari, Robert Kubica and Fernando Alonso rounded out the combined top ten, with the two Spaniards of particular note after eventful mornings. Alonso failed to post a time in the morning after suffering an engine failure that stranded him at turn six, but bounced back to claim tenth spot on 1min 36.604secs, one ahead of team-mate Felipe Massa. Alguersuari, meanwhile, put thoughts of team-mate Buemi's spectacular accident in the first session - in which the Toro Rosso lost both wheels under braking for the hairpin as the result of apparent upright failure - out of his mind to post a respectable time in the second STR5 once it had been fitted with the team's older upright design.
Sandwiching the Ferraris, Kubica and Renault team-mate Vitaly Petrov showed in both sessions that the yellow cars will again be a threat for the top ten shoot-out and potential points, while Sauber showed a continuation of its Sepang form to come in ahead of the Williams entries and Tonio Liuzzi's Force India. The Italian was again at a disadvantage, having been forced to sit out the morning session in favour of di Resta, but ended up edging the Scot by one place and eight-tenths on the timesheets.
Jarno Trulli took new team honours for Lotus as he and team-mate Heikki Kovalainen sandwiched Buemi, but there were problems for the Finn, who stopped out on track midway through the afternoon. Despite the HRT cars appearing to be the cause of much fist-shaking among the faster runners, Karun Chandhok managed to split the two Virgin drivers, with team-mate Bruno Senna bringing up the rear on his first visit to SIC.