Kimi Raikkonen beat Sebastian Vettel and Felipe Massa to the top spot in a close second Formula 1 practice session in Malaysia before rain intervened.
A heavy shower approaching the hour mark ensured that the 1m36.569s that Raikkonen had done on medium tyres 36 minutes in would stand as the fastest lap of the day.
Raikkonen's Lotus, Vettel's Red Bull and Massa's Ferrari had all taken turns in front during the dry section, and they ended up filling the final top three, covered by just 0.092 seconds.
The rain did not mean the end of the action. With similar conditions likely in both qualifying and the race, teams swiftly sent their drivers back out to sample both the wet track and the crossover to dry weather so they had some experience in case of rain later in the weekend.
The warm ambient temperature swiftly dried the track sufficiently for slicks, but the track was never quite good enough for drivers to beat their early times.
Behind the top three, Fernando Alonso edged out Mark Webber for fourth, with Romain Grosjean next up.
The Mercedes of Nico Rosberg and Lewis Hamilton were seventh and ninth, split by Paul di Resta.
Adrian Sutil held on to 10th despite a mechanical problem keeping his Force India in the garage during the rain delay.
Nearly everyone managed to avoid drama when the rain came, although Nico Hulkenberg did spin his slick-shod Sauber in the pitlane entry. Giedo van der Garde rotated on the track, spinning his Caterham onto the Turn 14 run-off.
Pos Driver Team Time Gap Laps
1. Kimi Raikkonen Lotus-Renault 1m36.569 28
2. Sebastian Vettel Red Bull-Renault 1m36.588s + 0.019s 27
3. Felipe Massa Ferrari 1m36.661s + 0.092s 33
4. Fernando Alonso Ferrari 1m36.985s + 0.416s 23
5. Mark Webber Red Bull-Renault 1m37.026s + 0.457s 29
6. Romain Grosjean Lotus Renault 1m37.206s + 0.637s 26
7. Nico Rosberg Mercedes 1m37.448s + 0.879s 32
8. Paul di Resta Force India-Mercedes 1m37.571s + 1.002s 30
9. Lewis Hamilton Mercedes 1m37.574s + 1.005s 32
10. Adrian Sutil Force India-Mercedes 1m37.788s + 1.219s 10
11. Sergio Perez McLaren-Mercedes 1m37.838s + 1.269s 21
12. Jenson Button McLaren-Mercedes 1m37.865s + 1.296s 29
13. Nico Hulkenberg Sauber-Ferrari 1m38.068s + 1.499s 31
14. Esteban Gutierrez Sauber-Ferrari 1m38.645s + 2.076s 23
15. Jean-Eric Vergne Toro Rosso-Ferrari 1m38.738s + 2.169s 31
16. Pastor Maldonado Williams-Renault 1m38.801s + 2.232s 27
17. Daniel Ricciardo Toro Rosso-Ferrari 1m38.904s + 2.335s 31
18. Jules Bianchi Marussia-Cosworth 1m39.508s + 2.939s 30
19. Valtteri Bottas Williams-Renault 1m39.660s + 3.091s 28
20. Charles Pic Caterham-Renault 1m40.757s + 4.188s 29
21. Giedo van der Garde Caterham-Renault 1m40.768s + 4.199s 32
22. Max Chilton Marussia-Cosworth 1m41.438s + 4.869s 23