Nico Rosberg set the fastest time of the opening practice session for the Australian Grand Prix as Sauber and Manor both failed to run.
Mercedes was predictably quick throughout the opening session, with Rosberg edging out team-mate Lewis Hamilton by just 0.029s in Melbourne. The two were significantly quicker than the rest of the field, with an advantage of more than a second over Valtteri Bottas in third place.
However, the main focus was on the bottom of the timing screens as four cars failed to run at all. Sauber continues to be embroiled in a court battle with Giedo van der Garde and as a result both cars stayed in the garage with further proceedings set to take place in the afternoon.
Manor was the other team to be confined to the garage for the whole session, with the team experiencing software issues with its Ferrari power unit. Manor is running the 2014 unit and has been facing a race against time to prepare for the opening race having exited administration in February.
Another team to struggle was McLaren, with further Honda problems limiting running. Jenson Button and Kevin Magnussen completed just 13 laps between them as the team had to end running early, with Button's best time almost five seconds slower than Rosberg.
While three teams were heavily limited in terms of mileage, Toro Rosso ensured both its rookie drivers completed plenty of laps as Carlos Sainz Jr was fourth quickest and Max Verstappen sixth with 31 laps each. Sebastian Vettel split the two STR10s, with all three drivers over 1.4s off the pace.
Felipe Massa was seventh after a long spell in the Williams garage, finishing the opening session ahead of Kimi Raikkonen, Pastor Maldonado and Daniel Ricciardo. The home favourite didn't enjoy the smoothest session as he completed just nine laps, spinning at the penultimate corner having put two wheels on the grass and complaining of drivability issues.
Aside from Ricciardo and the two McLarens, Romain Grosjean was the other driver to fail to reach double figures during the opening session as he was limited to five laps.
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| Pos | Driver | Team | Time | Gap | Laps |
| 01. | N. Rosberg | Mercedes | 1:29.557 | 19 | |
| 02. | L. Hamilton | Mercedes | 1:29.586 | 0.029 | 19 |
| 03. | V. Bottas | Williams | 1:30.748 | 1.191 | 20 |
| 04. | C. Sainz Jr | Toro Rosso | 1:31.014 | 1.457 | 32 |
| 05. | S. Vettel | Ferrari | 1:31.029 | 1.472 | 13 |
| 06. | M. Verstappen | Toro Rosso | 1:31.067 | 1.510 | 31 |
| 07. | F. Massa | Williams | 1:31.188 | 1.631 | 19 |
| 08. | K. Raikkonen | Ferrari | 1:31.310 | 1.753 | 14 |
| 09. | P. Maldonado | Lotus | 1:31.451 | 1.894 | 22 |
| 10. | D. Ricciardo | Red Bull | 1:31.570 | 2.013 | 9 |
| 11. | D. Kvyat | Red Bull | 1:32.073 | 2.516 | 18 |
| 12. | S. Perez | Force India | 1:32.247 | 2.690 | 22 |
| 13. | N. Hulkenberg | Force India | 1:32.261 | 2.704 | 19 |
| 14. | J. Button | McLaren | 1:34.542 | 4.985 | 6 |
| 15. | K. Magnussen | McLaren | 1:34.785 | 5.228 | 7 |
| 16. | R. Grosjean | Lotus | 5 | ||
| 17. | M. Ericsson | Sauber | |||
| 18. | F. Nasr | Sauber | |||
| 19. | W. Stevens | Manor | |||
| 20. | R. Merhi | Manor |
