Fernando Alonso took a popular victory in a Spanish Grand Prix dominated by strategy as he beat Kimi Raikkonen and team-mate Felipe Massa in Barcelona.
Having started fifth, a good start set up Alonso's charge and his Ferrari was quick enough to execute a four-stop strategy to beat the three-stopping Raikkonen. Massa, who started ninth, couldn't match his team-mate on the same strategy, but was a comfortable third as Sebastian Vettel - who finished fourth - struggled with tyre wear.
The only potential alarm for Alonso came late in the race when the team noticed a slow puncture on one of his tyres, but team principal Stefano Domenicali said "it was not a serious problem" as Alonso pit a few laps earlier to cover off Raikkonen,
Mercedes endured another difficult afternoon having started with both cars on the front row. Pole-sitter Nico Rosberg came home sixth while Lewis Hamilton plummeted down through the field to finish in 12th place. Rosberg did a good job on a three-stop strategy to hold off the attack of Paul di Resta in the closing laps, but Mercedes is still clearly far away from solving its tyre problems.
McLaren salvaged its weekend with a double points finish as Jenson Button three-stopped his way to eighth place, but the team called off the fight early on by telling Sergio Perez - close behind - not to waste his tyres attacking his team-mate.
Daniel Ricciardo rounded out the top ten after coming under pressure from Esteban Gutierrez late on, denying Gutierrez the first point of his Formula One career. The Sauber was clearly quick in race trim, however, as Gutierrez set the fastest lap of the race.
Alonso's victory was helped as he made a good start up to third jumping Raikkonen and Hamilton in turn three. Rosberg managed to hold onto the lead for the first stint as Hamilton dropped backwards, and at the first round of pit stops he retained the lead with Alonso emerging ahead of Vettel after stopping a lap earlier. From that point onwards though the Mercedes dropped away as Rosberg went for a three-stop strategy and Alonso and Vettel pushed harder on a four-stop.
Vettel was never really a threat to Alonso as he struggle to manage his tyres, with only Raikkonen seeming likely to challenge the Ferrari for victory as he came through on a three-stop strategy. Having led a number of times in the race, Raikkonen had to pit earlier than Alonso for the final time, allowing Alonso to retain a comfortable lead and ease home on fresher tyres.
Massa attempted a late push to try and catch the Lotus, but with tyres a concern eventually backed off and cruised home to third. Vettel took a lonely fourth place ahead of team-mate Mark Webber, who recovered from a bad start to take a solid haul of points. Di Resta's strategy saw him able to attack Rosberg but with overtaking tough on the Circuit de Catalunya he was unable to find a way past.
With the majority of drivers opting for a four-stop strategy, Pirelli's Paul Hembery admitted after the race that it was too many and that the tyre supplier would look to alter its compounds by the British Grand Prix.
The result closes up the championship with Raikkonen now just four points behind Vettel in the title chase and Alonso 17 points shy of Vettel. With Monaco offering a completely different challenge in two weeks' time, the title is all to play for.