Hamilton responded by increasing his speed when he switched to a higher-powered engine setting to keep Rosberg behind for his fourth victory in succession in 2014 and the 26th of his career.

The 2014 Spanish Grand Prix was the fifth of the 19 races of the 2014 Formula One World Championship, the 24th running of the event in Barcelona and the 44th edition since the inception of the series.

[13] Ferrari reverted to using a single pillar rear wing support on the F14 T's centre line, aimed at reducing airflow disturbance and increasing downforce, and therefore grip, produced by the bodywork.

[15] Sauber introduced a revised aerodynamic package version of its C33 chassis, which included a modified front wing, new side-pod fins, engine cover and deflectors, reducing the car's overall weight.

[16] For both of its E22 cars, Lotus brought a reconfigured engine mapping programme along with a revised cooling system and bodywork package and an updated rear wing.

[17] A total of 11 teams (each representing a different constructor) fielded two race drivers each with two extra participants driving solely in the first free practice session.

Daniel Ricciardo for Red Bull, Alonso, Rosberg, Kimi Räikkönen, McLaren's Kevin Magnussen, Lotus driver Pastor Maldonado, Sergio Pérez of Force India and Williams' Felipe Massa rounded out the top ten.

[23] Van Der Garde's brakes failed on the approach to turn one's run-off area; he avoided hitting the left-hand side wall at high speed.

[25] Vettel stopped at the side of turn six with a damaged wiring loom that forced him to miss the second session while his team rectified it.

Yellow flags were waved at the entry to the final corner when a chunk of rear bodywork around the exhaust system of Chilton's car detached, which was retrieved by a track marshal.

[27][28] After the session, Toro Rosso's Jean-Éric Vergne incurred a ten-place grid penalty because the stewards deemed him to have been released from the pit lane with an incorrectly attached right-rear wheel that detached in turn one.

[30] Hamilton, Alonso, Massa, Lotus' Romain Grosjean, Magnussen, Ricciardo, Button, Maldonado and Vettel completed the top ten.

During the session, where several drivers had rear grip issues, Chilton locked his front-left wheel and got stuck in the turn five outside gravel trap.

An improved car balance, grip and rear stability under braking qualified Räikkönen and his teammate Alonso sixth and seventh.

[33] Vettel did not set a lap time in the final session because of a gearbox fault that emerged when he exited his garage and stopped at turn three.

His Force India teammate Pérez was 11th after slower traffic compromised his final timed lap, which he aborted to conserve his tyre allocation.

[33] Maldonado failed to set a lap after he lost control of the rear of his car on the artificial grass at the exit of turn three and struck the inside concrete barrier, damaging his front right suspension and stopped the first session for seven minutes.

On lap six, Red Bull advised Ricciardo to drop back from Bottas so that he did not put additional stress on his tyres by driving in the aerodynamic turbulence created by the airflow of other cars for a long period of time.

[40][45] Ricciardo entered the pit lane for the medium compound tyres at the conclusion of lap 14 in an attempt to pass Bottas and stay on a two-stop strategy.

Williams elected not to bring Bottas into the pit lane in response and kept him on track to keep a consistent pace without sustaining rear tyre degradation.

[47] Rosberg lowered the deficit to Hamilton to 1.6 seconds by the time of his teammate's first pit stop at the end of lap 18 for the medium compound tyres and a minor front wing angle adjustment.

Massa made his second pit stop for the hard compound tyres on lap 28, meaning Vettel's aerodynamics could not be affected by other's cars negatively.

[40][45] At the end of lap 42, Hamilton ignored an instruction from Mercedes to enter the pit lane and asked for further adjustments to his front wing to counter a possible oversteer with a new set of tyres.

Hamilton locked his wheels braking for turn ten and ran wide on lap 65, allowing his teammate Rosberg to attempt an unsuccessful pass.

[47] He led Rosberg by six-tenths of a second on the final lap,[45] who attempted a pass with DRS but locked his tyres at turn ten,[40] allowing Hamilton to take his fourth win in succession in 2014 and the 26th of his career.

"[52] Third-placed Ricciardo stated Red Bull were aware they could not equal Mercedes' performance and that the team focused on tyre conservation.

[52] In the subsequent press conference, Hamilton said Mercedes' form of five victories in succession meant the team appeared stronger for the foreseeable future and was certain the journalists who criticised his move to the manufacturer in 2013 had changed their views.

Rosberg said there was a large amount of positive aspects to take forward from the race and was motivated to extract additional pace to beat Hamilton.

It was the second time in the season that a Mercedes driver used a forbidden engine setting after Rosberg did so at the Bahrain Grand Prix two races earlier.

[56] Räikkönen questioned over the radio the decision to change his strategy on the way back to the pit lane after the race due to his belief Alonso was being prioritised over him.