Brazilian GP: Nico Rosberg leads Mercedes one-two in damp practice

A late surge lifted Sebastian Vettel to third ahead of McLaren's Jenson Button, Ferrari's Fernando Alonso and Vettel's Red Bull team-mate Mark Webber.

The Red Bull duo had spent much of the session in the garage or on single-lap data runs, but both improved in the final 20 minutes.

Conditions largely dictated the order, with the first half hour proving the optimal time to run before rain returned and times consequently dropped significantly.

Rosberg epitomised that trend, setting an early 1m24.781s benchmark that would remain unbeaten for the remainder of the 90 minutes.

Hamilton moved into second moments later, just over four tenths of a second down on his team-mate.

Both men had moments even as they set their fastest times however: Rosberg went too deep into the Senna S immediately after going top for the first time, while Hamilton was the session's first spinner when he lost the rear of his Mercedes through the Descida do Lago.

Button also set his best time early on, but behind him Alonso bucked the session's overall pattern when he surged into fourth at the halfway mark, just as the rain began to worsen.

Red Bull meanwhile was yet to set any times, with Webber ensconced in the garage and Vettel electing to run cautious data-gathering laps on the hard slick compound.

At that point times were around two seconds per lap slower than the early running and the top order looked settled, but the session swung 20 minutes from the end when the rain abated.

Vettel and Webber were the chief movers: the Australian, competing in his final grand prix, slotted into fifth on his second run, but was then demoted when Vettel moved into third 10 minutes from the flag.

McLaren's departing Sergio Perez was seventh ahead of Toro Rosso's 2014 signing Daniil Kvyat, standing in for Daniel Ricciardo for first practice.

Lotus's Heikki Kovalainen and Sauber's in-the-spotlight Nico Hulkenberg were next up in ninth and 10th respectively.

Felipe Massa ended the first session of his Ferrari swansong in 11th, fractions ahead of Esteban Gutierrez and Romain Grosjean.

The conditions meant none of the teams were able to sample Pirelli's 2014 prototype slick tyre, with Vettel's data runs on the hard compound the only slick running of the session.

Pos Driver              Team                    Time       Gap     Laps  
 1. Nico Rosberg        Mercedes                1m24.781s           14   
 2. Lewis Hamilton      Mercedes                1m25.230s  +0.449s  13   
 3. Sebastian Vettel    Red Bull-Renault        1m25.387s  +0.606s  17   
 4. Jenson Button       McLaren-Mercedes        1m25.391s  +0.610s  25   
 5. Fernando Alonso     Ferrari                 1m25.593s  +0.812s  13   
 6. Mark Webber         Red Bull-Renault        1m25.797s  +1.016s  17   
 7. Sergio Perez        McLaren-Mercedes        1m25.946s  +1.165s  15   
 8. Daniil Kvyat        Toro Rosso-Ferrari      1m26.064s  +1.283s  17   
 9. Heikki Kovalainen   Lotus-Renault           1m26.133s  +1.352s  31   
10. Nico Hulkenberg     Sauber-Ferrari          1m26.232s  +1.451s  17   
11. Felipe Massa        Ferrari                 1m26.248s  +1.467s  15   
12. Esteban Gutierrez   Sauber-Ferrari          1m26.326s  +1.545s  28   
13. Romain Grosjean     Lotus-Renault           1m26.570s  +1.789s  28   
14. Jean-Eric Vergne    Toro Rosso-Ferrari      1m26.593s  +1.812s  22   
15. Adrian Sutil        Force India-Mercedes    1m27.115s  +2.334s  25   
16. Valtteri Bottas     Williams-Renault        1m27.269s  +2.488s  23   
17. Pastor Maldonado    Williams-Renault        1m27.358s  +2.577s  23   
18. James Calado        Force India-Mercedes    1m27.436s  +2.655s   9   
19. Giedo van der Garde Caterham-Renault        1m28.107s  +3.326s  18   
20. Charles Pic         Caterham-Renault        1m28.199s  +3.418s  17   
21. Jules Bianchi       Marussia-Cosworth       1m30.004s  +5.223s  24   
22. Rodolfo Gonzalez    Marussia-Cosworth       1m32.646s  +7.865s  19