Rosberg was quickest out of the blocks in the first half hour of the session as drivers lapped using the so-called FP130 set of ‘free’ premium tyres they are allowed for the opening 30 minutes of the session. He and Hamilton traded fastest times on a circuit that was noticeably dusty and lacking grip.

Vettel briefly ran quickest during that phase but soon slipped back to lap almost a second off the pace throughout. The four-time champion ended the session marginally ahead of team-mate Kimi Raikkonen, the gap between the two being just two hundredths of a second.

Toro Rosso had a productive opening outing at the Circuit de Barcelona Catalunya, with home racer Carlos Sainz enjoying a good run to fourth place, three tenths down on the Ferraris. Sainz was backed up by team-mate Max Verstappen, who set a time of 1:28.529 on his way to fifth place on the timesheet.

The junior Red Bull team eclipsed the main squad, with Daniil Kvyat setting the morning’s sixth-fastest lap with a time of 1:28.785, almost two seconds down on Rosberg’s P1 time.

The Russian ran a new nose on his RB11 but with the team facing continuing engine issues both he and team-mate Daniel put in limited running, with Kvyat logging just seven laps and Ricciardo, who finished ninth, posting nine.

The bulk of Ricciardo’s running was done late in the session as after just a single lap early in the 90 minutes he had reported a problem when he applied full throttle. The issue restricted him to the garage then until the final ten minutes of running.

The Red Bull pairing was split by Williams’ Felipe Massa, while Sauber’s Felipe Nasr completed the top 10 order.

Nico Hulkenberg slotted into P11 and the Force India driver was followed by a trip of reserve drivers. Ferrari academy driver Raffaele Marciello, standing in for Sauber’s Marcus Ericsson, was the quickest of the trio, recording a time of 1:29.630 to finish 2.6s off Rosberg.

He was followed by Jolyon Palmer who replaced Romain Grosjean at Lotus and Susie Wolff who stood in for Valtteri Bottas at Williams.

The lower end of the order saw the upgraded McLarens of Fernando Alonso and Jenson Button finish 15^th and 16^th respectively, while Sergio Perez was 17^th ahead of Lotus’ Pastor Maldonado and the twin Manor cars of Will Stevens and Roberto Merhi.

2015 Spanish Grand Prix – Free Practice 1
1 Nico Rosberg Mercedes 1:26.828s  28
2 Lewis Hamilton Mercedes 1:26.898s +0.07s 27
3 Sebastian Vettel Ferrari 1:27.806s +0.978s 21
4 Kimi Raikkonen Ferrari 1:27.832s +1.004s 16
5 Carlos Sainz Toro Rosso 1:28.132s +1.304s 27
6 Max Verstappen Toro Rosso 1:28.529s +1.701s 23
7 Daniil Kvyat Red Bull Racing 1:28.785s +1.957s 7
8 Felipe Massa Williams 1:28.831s +2.003s 21
9 Daniel Ricciardo Red Bull Racing 1:29.075s +2.247s 9
10 Felipe Nasr Sauber 1:29.140s +2.312s 14
11 Nico Hulkenberg Force India 1:29.409s +2.581s 20
12 Raffaele Marciello Sauber 1:29.630s +2.802s 15
13 Jolyon Palmer Lotus 1:29.676s +2.848s 21
14 Susie Wolff Williams 1:29.708s +2.88s 22
15 Fernando Alonso McLaren 1:29.813s +2.985s 22
16 Jenson Button McLaren 1:29.817s +2.989s 22
17 Sergio Perez Force India 1:30.096s +3.268s 19
18 Pastor Maldonado Lotus 1:30.110s +3.282s 7
19 Will Stevens Manor 1:32.471s +5.643s 22
20 Roberto Merhi 1:32.647s +5.819s 20