Play F1 | Nico Rosberg topped the opening practice session of the 2015 season in Australia

The 2014 runner-up set the pace with a lap of 1:29.557 on the medium tyre, in a session dominated by the two Mercedes team-mates.

Lewis Hamilton was second in the sister W06 Hybrid, just +0.029 shy of Rosberg, to ensure the reigning champions ended the first session of 2015 with a 1-2.

Williams’ Valtteri Bottas was their closest rival, though he remained over a second off the pace with his 1:30.748 – the only driver bar Mercedes to dip below the 1:31 mark.

The Toro Rosso rookies Max Verstappen and Carlos Sainz were the two most active drivers during the session, completing 63 laps between them as they got their first taste of the Albert Park track. The pair were separated by just 0.053s – as well as the Ferrari of Sebastian Vettel – and in doing so made a solid start to their F1 careers with the fourth and sixth fastest times.

Meanwhile, the senior Red Bull team appeared to struggle, with Daniel Ricciardo complaining about the driveability of the Renault power unit and suffering a spin at the penultimate corner with 30 minutes remaining. While Renault has worked on boosting power ahead of the season, the delivery of the power was still offering the drivers some surprises on Friday. Ricciardo’s fastest time was quick enough for 10th behind the Lotus of Pastor Maldonado, the Ferrari of Kimi Raikkonen and the Williams of Felipe Massa.

McLaren continued its stop-start search for reliability, but despite hitting the track early in the session only managed 13 laps between both drivers. Of the cars that set a time they were only quicker than Romain Grosjean, whose Lotus had an issue until the final moments of the session when he completed five laps.

Pos	Driver	Car	Time	Gap	Laps
1	Nico Rosberg	Mercedes	1m29.557s	–	19
2	Lewis Hamilton	Mercedes	1m29.586s	0.029s	19
3	Valtteri Bottas	Williams/Mercedes	1m30.748s	1.191s	20
4	Carlos Sainz Jr.	Toro Rosso/Renault	1m31.014s	1.457s	32
5	Sebastian Vettel	Ferrari	1m31.029s	1.472s	13
6	Max Verstappen	Toro Rosso/Renault	1m31.067s	1.510s	31
7	Felipe Massa	Williams/Mercedes	1m31.188s	1.631s	19
8	Kimi Raikkonen	Ferrari	1m31.310s	1.753s	14
9	Pastor Maldonado	Lotus/Mercedes	1m31.451s	1.894s	22
10	Daniel Ricciardo	Red Bull/Renault	1m31.570s	2.013s	9
11	Daniil Kvyat	Red Bull/Renault	1m32.073s	2.516s	18
12	Sergio Perez	Force India/Mercedes	1m32.247s	2.690s	22
13	Nico Hulkenberg	Force India/Mercedes	1m32.261s	2.704s	19
14	Jenson Button	McLaren/Honda	1m34.542s	4.985s	6
15	Kevin Magnussen	McLaren/Honda	1m34.785s	5.228s	7
16	Romain Grosjean	Lotus/Mercedes	2m17.782s	48.225s	5