Spanish GP: Hamilton leads Mercedes 1-2 in FP1

Hamilton clocked a 1m21.521s on the medium tyre, just 0.029s quicker than teammate Valtteri Bottas at Barcelona.

Ferrari's Kimi Raikkonen was the closest challenger to Mercedes, which is running radical scoop vanes on the nose, but he was nearly a second adrift.

The Mercedes drivers were evenly matched throughout the session, with Hamilton holding the edge by 0.089s on the early runs on the hard tyre.

After their first flying laps on the mediums, Hamilton and Bottas did a cool-down lap before going again but both failed to improve their times.

The duo clocked 58 laps between them in a smooth session for the world champion outfit, but it was not so positive for rival Ferrari and McLaren.

Championship leader Sebastian Vettel stopped at the exit of the pitlane, reporting an issue with the gearbox with just over an hour to go.

After a short time in the garage, the German rejoined the fray and ended the session fourth quickest, just over a tenth adrift of his teammate.

Fernando Alonso's session lasted just a handful of corners, his car snapping approaching Turn 3 with smoke and fluid pouring his his Honda power unit.

Honda said it was an oil leak and in a bid to ensure he gets out for second practice chose to change the engine while it investigated the problem.

Alonso's teammate Stoffel Vandoorne had a more fruitful session, clocking up 24 laps and the 12th quickest time.

Max Verstappen was the best of the Red Bulls in fifth, 1.185s off the pace and four tenths clear of teammate Daniel Ricciardo.

Kevin Magnussen beat Romain Grosjean to seventh, but the former's session ended a few minutes early when he parked the Haas at the edge of the track at Turn 4.

Renault's Nico Hulkenberg and Toro Rosso's Carlos Sainz completed the top 10.

Sergey Sirotkin, who took over Jolyon Palmer's Renault for this session, managed 10 laps and the 19th quickest time before his session was curtailed by a water leak.

Cla	Driver	Chassis	Engine	Laps	Time	Gap
1	Lewis Hamilton	Mercedes	Mercedes	28	1'21.521
2	Valtteri Bottas	Mercedes	Mercedes	30	1'21.550	0.029
3	Kimi Raikkonen	Ferrari	Ferrari	24	1'22.456	0.935
4	Sebastian Vettel	Ferrari	Ferrari	23	1'22.600	1.079
5	Max Verstappen	Red Bull	TAG	22	1'22.706	1.185
6	Daniel Ricciardo	Red Bull	TAG	17	1'23.084	1.563
7	Kevin Magnussen	Haas	Ferrari	22	1'23.670	2.149
8	Romain Grosjean	Haas	Ferrari	23	1'23.758	2.237
9	Nico Hulkenberg	Renault	Renault	24	1'23.993	2.472
10	Carlos Sainz Jr.	Toro Rosso	Renault	21	1'24.004	2.483
11	Sergio Perez	Force India	Mercedes	23	1'24.188	2.667
12	Esteban Ocon	Force India	Mercedes	22	1'24.324	2.803
13	Stoffel Vandoorne	McLaren	Honda	24	1'24.400	2.879
14	Felipe Massa	Williams	Mercedes	34	1'24.618	3.097
15	Daniil Kvyat	Toro Rosso	Renault	18	1'24.642	3.121
16	Marcus Ericsson	Sauber	Ferrari	23	1'24.966	3.445
17	Pascal Wehrlein	Sauber	Ferrari	24	1'25.182	3.661
18	Lance Stroll	Williams	Mercedes	34	1'25.919	4.398
19	Sergey Sirotkin	Renault	Renault	10	1'26.293	4.772
20	Fernando Alonso	McLaren	Honda	1