Mercedes' Michael Schumacher set the fastest time in the second Free Practice session of the weekend's Chinese Grand Prix (the third round of the 2012 FIA Formula 1 World Championship); the seven-time world champion finished in front of McLaren's Lewis Hamilton, who set the fastest time in the morning session.
Meanwhile, the Red Bull duo of reigning champion Sebastian Vettel and his team mate Mark Webber were third and fourth, respectively and Schumacher's team mate Nico Rosberg took fifth ahead of McLaren's Jenson Button.
Lotus' Kimi Raikkonen finished a disappointing 13th and his team admitted they were slightly perplexed by the lack of performance. They suspected the set-up was not suited to colder track temperatures - both air and surface readings were less than 15 degrees. Raikkonen's team mate Romain Grosjean could only manage 15th.
A number of the other drivers also suffered tyre lock-ups on the bumpy circuit, with Timo Glock having the most unnerving accident of the session.
Gluck lost his nose cone as he hit a bump going into Turn One, ran straight off the track and into the barriers. He was unhurt but with the drivers struggling at Turn One and the hairpin at Turn 14, there is still much to be done to get set-ups right for Saturday's qualifying session.
Meanwhile, Schumacher and Rosberg have been cleared to continue using a controversial rear wing, which some rivals felt infringed on the regulations. A formal protest from the Lotus team was rejected by FIA stewards.
The second practice session was much busier than the first as the track was dry throughout.
In the morning session, drivers had struggled on the slippery track and the best times were not set until the top drivers were able to use slick dry-weather tyres late on. Hamilton finished a full second faster than Nico Rosberg in second and Schumacher in third.
There will be another Free Practice session on Saturday, ahead of qualifying on the same day. The race is due to start on Sunday. McLaren and Red Bull are expected to continue their rivalry at the top of the grid.
Top Ten Times from Free Practice 2:
1. Michael Schumacher, Mercedes - 1'35.973 (32 laps)
2. Lewis Hamilton, McLaren-Mercedes - 1'36.145 (29 laps)
3. Sebastian Vettel, Red Bull-Renault - 1'36.160 (27 laps)
4. Mark Webber, Red Bull-Renault - 1'36.433 (24 laps)
5. Nico Rosberg, Mercedes - 1'36.617 (31 laps)
6. Jenson Button, McLaren-Mercedes - 1'36.711 (28 laps)
7. Kamui Kobayashi, Sauber-Ferrari - 1'36.956 (28 laps)
8. Paul di Resta, Force India-Mercedes - 1'36.966 (31laps)
9. Nico Hulkenberg, Force India-Mercedes - 1'37.191 (31 laps)
10. Fernando Alonso, Ferrari - 1'37.316 - 1.343 (32 laps)
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