Lewis Hamilton set the fastest time in second practice for the Chinese Grand Prix, but Ferrari's Fernando Alonso remained in the hunt just 0.141s off the Mercedes.
After setting the fastest time in FP1, Alonso split the two Mercedes in the second session as all the drivers produced more representative times using the softer compound tyres. Rosberg was third fastest, 0.270s adrift of Alonso and less than a tenth clear of the Red Bull of Daniel Ricciardo in fourth.
However, based on the previous three Friday practice sessions, Mercedes may well be holding something back for qualifying day. Ferrari's apparent resurgence could be explained by the nature of the track, which punishes the front tyres much more than the rear tyres and is not as dependent on power and traction - the F14 T's weaknesses - as the Bahrain International Circuit two weeks ago.
Hamilton spent the start of the session in the garage as his team fixed a suspension issue that emerged in the morning session, but was soon up to speed and set his quick lap on his first attempt on soft tyres. Rosberg's quick lap on fresh softs was slightly hampered by a yellow flag in the final sector after Pastor Maldonado put his Lotus in the wall on the pit entry.
After a bizarre off-track moment in FP1, when he appeared to take his eyes off the road, Maldonado overcooked his entry to the pit lane midway through the afternoon session and ran wide and into the wall. The damage to the suspension of the Lotus put an end to his day and left him with less than half the mileage of all the other drivers in FP2.
Sebastian Vettel was fifth fastest and over 0.2s off his team-mate Ricciardo, but the Red Bull did appear to be easy on its tyres, with Ricciardo able to complete a whopping 23-lap stint on the soft tyres with consistent times. Felipe Massa was sixth fastest as Williams appears to still be in the hunt for the top spots, ahead of the second Ferrari of Kimi Raikkonen. Ferrari fixed the suspension issue Raikkonen had in FP1, but he was on a different run programme to Alonso, which could explain the gap to his team-mate.
Jenson Button was eighth fastest in his McLaren while Romain Grosjean showed signs of a step forward for Lotus in ninth place. Toro Rosso's Daniil Kvyat rounded off the top ten ahead of the highest-placed Force India of Nico Hulkenberg in 11th place.