Ferrari duo Felipe Massa and Kimi Raikkonen finished top of the timesheets after free practice for Sunday's Australian Grand Prix.
The team carried over their impressive winter form with Massa lapping Albert Park in one minute 27.353 seconds with Raikkonen 0.397secs behind.
British rookie Lewis Hamilton was an encouraging third for McLaren with team-mate Fernando Alonso eighth.
But Jenson Button's Honda showed a lack of pace as he finished down in 14th.
There could also be some cause for concern in the Renault garage after rookie Heikki Kovalainen held up the second practice session as he spun off the track.
Team-mate Giancarlo Fisichella also halted on the track in the closing seconds after setting the fourth fastest time.
"Both cars suffered fuel pressure problems," said director of engineering Pat Symonds. "The cause is currently unexplained."
"It is a steep learning curve but this is testing so qualifying is what matters"
Alonso, champion for the past two seasons with Renault, had been quickest in opening practice in his McLaren but failed to build on that in the second session.
His team-mate Hamilton refused to get carried away after a controlled drive saw him cope well with the slippery conditions early on and then finish third fastest in the afternoon.
"It is a harder circuit when it is wet but things went pretty smoothly, especially in the second session," said Hamilton, 22.
"It is a steep learning curve but this is testing so tomorrow is what matters so we will see what happens then."
Honda's Rubens Barrichello also left the track after spinning unchallenged in the late session and he qualified in 15th behind team-mate Button.
606: DEBATE
Worryingly for the team both drivers set slower lap times than Takuma Sato and Britain's Anthony Davidson, who finished 11th, in the Honda-backed Super Aguris.
David Coulthard clocked 10th fastest for Red Bull while BMW Sauber duo Nick Heidfeld (fifth) and Robert Kubica (ninth) and Williams pair Alexander Wurz (sixth) and Nico Rosberg (eighth) rounded out the top 10.
Results of second free practice from Melbourne:
1. Felipe Massa (Brazil) Ferrari 1:27.353
2. Kimi Raikkonen (Finland) Ferrari 1:27.750
3. Lewis Hamilton (Britain) McLaren-Mercedes 1:27.829
4. Giancarlo Fisichella (Italy) Renault 1:27.941
5. Nick Heidfeld (Germany) BMW Sauber 1:27.970
6. Alexander Wurz (Austria) Williams-Toyota 1:27.981
7. Fernando Alonso (Spain) McLaren-Mercedes 1:28.040
8. Nico Rosberg (Germany) Williams-Toyota 1:28.055
9. Robert Kubica (Poland) BMW Sauber 1:28.281
10. David Coulthard (Britain) Red Bull-Renault 1:28.495
11. Anthony Davidson (Britain) Super Aguri-Honda 1:28.727
12. Jarno Trulli (Italy) Toyota 1:28.921
13. Takuma Sato (Japan) Super Aguri-Honda 1:29.009
14. Jenson Button (Britain) Honda 1:29.066
15. Rubens Barrichello (Brazil) Honda 1:29.542
16. Ralf Schumacher (Germany) Toyota 1:29.574
17. Mark Webber (Australia) Red Bull-Renault 1:29.801
18. Heikki Kovalainen (Finland) Renault 1:30.097
19. Scott Speed (U.S.) Toro Rosso-Ferrari 1:30.383
20. Christijan Albers (Netherlands) Spyker-Ferrari 1:31.108
21. Adrian Sutil (Germany) Spyker-Ferrari 1:31.175
22. Vitantonio Liuzzi (Italy) Toro Rosso-Ferrari 1:31.693
Follow live coverage of qualifying at 0300 GMT on Saturday and the race at the same time on Sunday on the BBC Sport website and Radio Five Live