Lewis Hamilton and Jenson Button gave Vodafone McLaren Mercedes day one bragging rights in Melbourne, but had their track time limited by the onset of rain in the second of the two 90-minute practice sessions.
Having slipped to seventh position late in the 'morning' session, Hamilton came storming back to lower the benchmark lap time by over a second, eventually clocking 1min 25.801secs in the midst of the 13 laps he completed later in the day. The Briton was the only driver to duck under 1min 26secs all day, although team-mate Button came close as he claimed second spot in 1min 26.076secs. Both drivers set their times in the early part of the session, before the rain made it near impossible for anyone to match them.
After the various showers had relented, improvements were possible, as Mark Webber, amongst others showed, but not to the extent of breaking 1min 26secs. The Australian, hoping for a home win this weekend after several seasons of heartache, got as close as anyone to the McLarens, but had to make do with a 1min 26.248secs.
Michael Schumacher, having set an unofficial fastest lap under the red flags that blighted the earlier session, was among the first out after the rain abated and appeared set for third spot before Webber shaved three-tenths from his time, while Vitaly Petrov, on his first day of running at Albert Park, also came close to deposing the German, ending the day just a couple of tenths shy in fifth place.
The Russian's team-mate, Robert Kubica, could only manage eleventh spot after topping the early session for Renault, but his 'morning' lap proved good enough for tenth on the combined list. With Sebastien Buemi, Adrian Sutil - whose only session of the day was interrupted by the rain - Tonio Liuzzi and Rubens Barrichello filling the remaining top ten slots, Nico Rosberg was left to take eleventh on the day, the first time he has been out-paced by Mercedes team-mate Schumacher this season.
Pedro de la Rosa raised BMW Sauber morale after a difficult session by matching Kubica's afternoon time to the thousandth, while team-mate Kamui Kobayashi backed the Spaniard up in 13th place following a morning in which he triggered two red flag periods.
While Felipe Massa sneaked in ahead of the German on the overall charts, Nico Hulkenberg had a couple of illustrious names in his wake as Sebastian Vettel and Fernando Alonso restricted to 16th and 15th respectively, swapping places on the combined chart courtesy of the Red Bull man's superior 'morning' time. Vettel, however, had lost time with a spin midway through the session as he tried to keep pace with one of the Ferraris.
Heikki Kovalainen claimed the fastest newcomer time for Lotus, trailing the slowest of the established runners by just over a second, and Hamilton by four, and ended the afternoon session ahead of Toro Rosso's Jaime Alguersuari. Timo Glock hauled Virgin Racing off the bottom of the pack after missing most of the earlier session, leaving the bad luck to team-mate Lucas di Grassi and HRT pair Karun Chandhok and Bruno Senna, none of whom completed a flying lap.