Romain Grosjean again showed his wet weather ability by topping a wet final free practice session at the Australian Grand Prix, but the bigger story of a fraught hour was the sight of Sebastian Vettel stopping on track with mechanical problems.
The German had set the pace throughout Friday, leading to pessimists claiming that he would run away with both qualifying and the race, but the return of familiar warnings from the pit-wall to 'pull off and shut down' – as heard on several occasions in 2012 – will give Red Bull's rivals some cause for hope. A sensor glitch was the official reason for Vettel's exit, which came inside the final ten minutes of the hour-long session and left the reigning world champion only twelfth on the timesheets.
In Vettel's absence, it was Grosjean who emerged fastest of all, the Lotus driver's 1min 26.929secs benchmark being set in the opening few minutes, when the Albert Park circuit was still dry. Team attempted to squeeze as much slick-shod running into that period as possible, with rain clearly visible on both the radar and horizon. Any real preparation for qualifying was largely scuppered by the precipitation, however, and some drivers received no dry running at all.
Grosjean's best lap was good enough to keep both Ferraris at bay, with Fernando Alonso just 0.071secs adrift of the Frenchman and Felipe Massa third overall, a couple of tenths further back. The changing conditions, however, ensured that the field was well-spread when it came to times, with Lewis Hamilton some 20 seconds off the pace at the foot of the table having only run in the worst of the weather.
Paul di Resta kept up Force India's strong start to the weekend in fourth overall, but was six-tenths behind Grosjean and only just ahead of the second Lotus of Kimi Raikkonen, which rounded out the top five. The two Toro Rossos, with Daniel Ricciardo ahead of Jean-Eric Vergne, Adrian Sutil's Force India and the Saubers of Nico Hulkenberg and rookie Esteban Gutierrez – who posted identical 1min 28.253secs marks - completed the top ten.
While Lotus and Ferrari managed to lap at the right time in the session, the other expected frontrunners found themselves some way down the order, with Mercedes' Nico Rosberg eleventh, just ahead of the two Red Bulls of Vettel and Mark Webber. McLaren's disappointing weekend also continued, despite Jenson Button hoping that rain may suit the MP4-28, with the Briton 17th, one spot ahead of new team-mate Sergio Perez.
The shake-up allowed several unfancied names to appear a little higher than normal - with Jules Bianchi, Giedo van der Garde and Charles Pic slotting in between the Red Bulls and McLarens – although that is not expected to have any bearing on qualifying, which looks set to also take place on a wet circuit.