MELBOURNE, Australia (AP) -- Reigning Formula One champion Lewis Hamilton set the fastest time in Saturday's pre-qualifying practice session at the season-opening Australian Grand Prix, narrowly topping his Mercedes teammate Nico Rosberg and Ferrari's Sebastian Vettel.
The top three were separated by less than a quarter of a second, setting up a potentially tight battle for pole position later in the day, when the new format of rolling eliminations makes its debut.
The Toro Rosso drivers Carlos Sainz Jr. and Max Verstappen were fourth- and sixth-fastest respectively, either side of Ferrari's Kimi Raikkonen.
It was a very busy session because rain on Friday meant there was little opportunity to test tires and car settings. So eager were teams to maximize time on the track that Manor's Rio Haryanto and Romain Grosjean of Haas collided in pit lane on their way out of the garages at the start of the hour. The damage to Grosjean's car meant he missed the first half of the session.
Williams' drivers Valtteri Bottas and Felipe Massa were seventh and ninth on the time sheets, separated by local favorite Daniel Ricciardo of Red Bull. Force India's Sergio Perez completed the top 10.
In the new system of qualifying, drivers will get a few minutes in each session to set a lap time -- seven minutes in Q1, six minutes in Q2 and five in Q3 -- before the slowest drivers are eliminated, one every 90 seconds.