McLaren's Lewis Hamilton set the fastest time in Friday's afternoon practice for the Australian Grand Prix by a comfortable margin of 0.9 seconds, while local hero Mark Webber took a surprise second place for Red Bull.
Morning pacesetter Kimi Raikkonen was content to spend most of the session working on longer runs, and ended up only sixth fastest in his Ferrari, although his time from session one remained the quickest of the day.
Felipe Massa took third for Ferrari despite a wild spin late on, with McLaren's Heikki Kovalainen fourth and David Coulthard confirming Red Bull's potential with fifth position.
Webber occupied the top spot for the majority of the session, having hit the front after half an hour when he produced a 1:27.614 lap to beat Hamilton's initial benchmark by 0.128 seconds. The Australian then went faster still a quarter of an hour later, improving to 1:27.473.
The big names tried and failed to beat it, even when on soft tyres - although their slower laptimes relative to this morning's session suggested that heavier fuel loads were now being carried.
Massa moved up to second position, then had to abandon a subsequent effort after running very wide on the exit of Turn 12. The Ferrari eventually looped into a spin across the gravel, but missed the wall and was able to rejoin and cruise back to the pits.
Both McLarens also came close to Webber's time only to fall short, but then in the final minute of the session Hamilton improved his time by over a second, producing a 1:26.559 to end the afternoon on top.
Jarno Trulli had looked set for fifth place for Toyota until he put a wheel on the grass under braking for Turn 3 with 10 minutes remaining and spun into the gravel. He managed to hold on to seventh as others improved.
Williams put their troubled morning behind them to take eighth place with Nico Rosberg, although his teammate Kazuki Nakajima could only manage 16th.
Force India had a promising afternoon, with both cars in the top ten early on and Giancarlo Fisichella leaping into ninth with his last run.
Timo Glock completed the top ten for Toyota, ahead of Honda's Jenson Button, Nick Heidfeld in the fastest of the BMWs, and Fernando Alonso, who slipped right back to 13th for Renault having been in the top six this morning.
Many drivers visited the gravel traps and grass run-off areas as they acclimatised to the dusty track without traction control and assisted engine braking.
Heidfeld, Adrian Sutil, Coulthard, Nakajima, Rosberg, Fisichella, Alonso and Takuma Sato all went off the road at least once, but managed to continue without drama.
Pos Driver Team Time Laps
1. Hamilton McLaren-Mercedes (B) 1:26.559 33
2. Webber Red Bull-Renault (B) 1:27.473 + 0.914 27
3. Massa Ferrari (B) 1:27.640 + 1.081 29
4. Kovalainen McLaren-Mercedes (B) 1:27.683 + 1.124 28
5. Coulthard Red Bull-Renault (B) 1:28.037 + 1.478 26
6. Raikkonen Ferrari (B) 1:28.208 + 1.649 28
7. Trulli Toyota (B) 1:28.292 + 1.733 22
8. Rosberg Williams-Toyota (B) 1:28.352 + 1.793 31
9. Fisichella Force India-Ferrari (B) 1:28.469 + 1.910 32
10. Glock Toyota (B) 1:28.582 + 2.023 28
11. Button Honda (B) 1:28.632 + 2.073 30
12. Heidfeld BMW Sauber (B) 1:28.731 + 2.172 32
13. Alonso Renault (B) 1:28.779 + 2.220 37
14. Barrichello Honda (B) 1:28.849 + 2.290 28
15. Kubica BMW Sauber (B) 1:28.860 + 2.301 35
16. Nakajima Williams-Toyota (B) 1:29.077 + 2.518 33
17. Sutil Force India-Ferrari (B) 1:29.161 + 2.602 32
18. Vettel Toro Rosso-Ferrari (B) 1:29.193 + 2.634 40
19. Piquet Renault (B) 1:29.518 + 2.959 14
20. Bourdais Toro Rosso-Ferrari (B) 1:29.605 + 3.046 11
21. Sato Super Aguri-Honda (B) 1:30.663 + 4.104 16
22. Davidson Super Aguri-Honda (B) 1:31.527 + 4.968 8
All timing unofficial