Spanish GP: Lewis Hamilton leads first practice for Mercedes

The Mercedes driver ensured it was a British 1-2 at the top of the timing sheets as he finished 0.868s ahead of McLaren's Jenson Button.

Button held the fastest time for the majority of the Friday morning session recording his best time on the hour mark.

The McLaren driver was stationed at the top of the timesheets until his compatriot Hamilton set the fastest time five minutes from the end of the session.

There were problems for Sebastian Vettel, who sat out nearly the entire practice period after an electrical issue halted his running and he pulled to the side of the track at Turn 5, just 25 minutes into FP1.

The German had only completed four laps when the problem struck his car and he ended up with the 20th fastest time.

Nico Rosberg could only manage the fifth fastest time after he suffered a lack of running due to a problem with his Mercedes power unit.

Behind Button, Daniel Ricciardo was third fastest in his Red Bull ahead of Fernando Alonso, who was visibly hustling his Ferrari around the Spanish GP circuit.

His team-mate Kimi Raikkonen was sixth ahead of the second McLaren of Kevin Magnussen.

There was drama for Giedo van der Garde when he suffered a partial brake failure at Turn 1 and ran through the gravel at high speed, just missing the barriers on the outside of the corner.

Sauber's reserve driver was in the car in place of Esteban Gutierrez for FP1. He was able to continue to the pits unharmed.

The opening practice session of the weekend was the first chance for all the teams to try test the performance of their upgrades.

There was a bizarre moment for Sergio Perez when his left rear view mirror broke and came into his cockpit, forcing the Force India driver into the pits.

Pos Driver                Team                  Time       Gap    Laps
 1. Lewis Hamilton        Mercedes              1m27.023s           17
 2. Jenson Button         McLaren-Mercedes      1m27.891s  +0.868s  26
 3. Daniel Ricciardo      Red Bull-Renault      1m27.973s  +0.950s  21
 4. Fernando Alonso       Ferrari               1m28.128s  +1.105s  23
 5. Nico Rosberg          Mercedes              1m28.168s  +1.145s   9
 6. Kimi Raikkonen        Ferrari               1m28.337s  +1.314s  19
 7. Kevin Magnussen       McLaren-Mercedes      1m28.423s  +1.400s  27
 8. Pastor Maldonado      Lotus-Renault         1m28.744s  +1.721s  34
 9. Sergio Perez          Force India-Mercedes  1m28.779s  +1.756s  18
10. Felipe Massa          Williams-Mercedes     1m28.791s  +1.768s  13
11. Daniil Kvyat          Toro Rosso-Renault    1m28.792s  +1.769s  24
12. Nico Hulkenberg       Force India-Mercedes  1m28.828s  +1.805s  17
13. Jean-Eric Vergne      Toro Rosso-Renault    1m28.859s  +1.836s  24
14. Felipe Nasr           Williams-Mercedes     1m29.272s  +2.249s  15
15. Adrian Sutil          Sauber-Ferrari        1m29.688s  +2.665s  16
16. Jules Bianchi         Marussia-Ferrari      1m29.820s  +2.797s  22
17. Romain Grosjean       Lotus-Renault         1m29.444s  +2.421s  21
18. Giedo van der Garde   Sauber-Ferrari        1m30.440s  +3.417s  21
19. Max Chilton           Marussia-Ferrari      1m30.748s  +3.725s  19
20. Sebastian Vettel      Red Bull-Renault      1m30.942s  +3.919s   4
21. Kamui Kobayashi       Caterham-Renault      1m30.997s  +3.974s  22
22. Marcus Ericsson       Caterham-Renault      1m31.421s  +4.398s  22