Chasing his fourth successive victory this weekend, Lewis Hamilton's Spanish GP got off to a perfect start with back-to-back P1s in practice.
Friday's afternoon session at the Circuit de Barcelona-Catalunya got underway a driver short as Sebastian Vettel did not take to the track in light of his earlier problems.
"Due to an electrical problem that has damaged the wiring loom of Car No. 1, Sebastian will not be able to take part in FP2," Red Bull said on Twitter. "The Team will use the time to fix it to be ready for FP3 tomorrow."
The remaining 21 drivers quickly got down to work with Romain Grosjean getting proceedings underway with a 1:30. But as more drivers ventured out he quickly dropped down the order.
Kevin Magnussen and Jenson Button both had a brief spell in the P1 slot before Lewis Hamilton came flying through with a 1:27.448. He lowered that to a 1:27.061 while Nico Rosberg made it a Mercedes 1-2 ahead of Daniel Ricciardo, Fernando Alonso and Kimi Raikkonen.
Max Chilton ran into trouble when, on his second lap of the afternoon, was told to slowly bring his car into the pits as he had an "engine problem." He ventured out a bit later only to be told to again pit as "we still have an engine problem." He was able to do some running later in the session.
Pastor Maldonado was the first driver out on the medium tyres and jumped to fourth, still eight-tenths behind Hamilton. Ricciardo was the first of the front runners to make the swap and he went quickest on a 1:26.509. Raikkonen improved to third on his first run but it was again all change as moments later Rosberg crossed the line with a 1:25.973. And then came Hamilton with a 1:25.524.
Swapping to heavier fuel loads and race simulations for the final 30 minutes of FP2, Hamilton had the far better pace even compared to his team-mate Nico Rosberg. The Brit was lapping in the 1:30s while Rosberg was down in the 1:33s.
Meanwhile, Maldonado's session came to an end a few minutes early with a gearbox problem while Jean-Eric Vergne's ended when the rear right wheel came off his Toro Rosso as he left the pits for a final run.
01 Lewis Hamilton Mercedes 1:25.524 32 laps
02 Nico Rosberg Mercedes 1:25.973 +0.449 36 laps
03 Daniel Ricciardo Red Bull 1:26.509 +0.985 37 laps
04 Fernando Alonso Ferrari 1:27.121 +1.597 33 laps
05 Kimi Raikkonen Ferrari 1:27.296 +1.772 32 laps
06 Kevin Magnussen McLaren 1:27.788 +2.264 36 laps
07 Jenson Button McLaren 1:27.811 +2.287 29 laps
08 Felipe Massa Williams 1:27.824 +2.300 30 laps
09 Pastor Maldonado Lotus 1:27.866 +2.342 42 laps
10 Daniil Kvyat Toro Rosso 1:28.049 +2.525 34 laps
11 Nico Hulkenberg Force India 1:28.074 +2.550 30 laps
12 Jean-Eric Vergne Toro Rosso 1:28.246 +2.722 30 laps
13 Adrian Sutil Sauber 1:28.284 +2.760 32 laps
14 Valtteri Bottas Williams 1:28.698 +3.174 33 laps
15 Esteban Gutierrez Sauber 1:29.105 +3.581 24 laps
16 Sergio Perez Force India 1:29.129 +3.605 34 laps
17 Romain Grosjean Lotus 1:29.493 +3.969 26 laps
18 Jules Bianchi Marussia 1:29.991 +4.467 26 laps
19 Max Chilton Marussia 1:31.148 +5.624 28 laps
20 Kamui Kobayashi Caterham 1:31.338 +5.814 38 laps
21 Marcus Ericsson Caterham 1:31.586 +6.062 38 laps
22 Sebastian Vettel Red Bull No time