Nico Rosberg shows his class to close the gap on Lewis Hamilton at the top
Nico Rosberg completed a "fantastic weekend" to put himself firmly in the title picture as he took his first win of the season at the Spanish Grand Prix.
The German had struggled to get close to Mercedes team-mate Lewis Hamilton in the opening four races of the year but was back to his best in Barcelona, winning from pole to close to 20 points behind the reigning champion.
A poor start from Hamilton instantly gave Rosberg the upper hand on a circuit notoriously bad for overtaking - with Sebastian Vettel also getting ahead of the Brit before the first corner.
Despite then suffering a long first pit stop, a switch to a three-stop strategy was enough for Hamilton to jump Vettel and take second place, with the German once again occupying the final step of the podium.
Rosberg never looked in danger of relinquishing the lead and won by 17.5 seconds after promising to deliver a "complete weekend" for the first time so far this season.
Last year's runner-up in the drivers' championship had played second fiddle to Hamilton until this race but looked sharper in Bahrain three weeks ago and carried that into the opening European race of the campaign.
"It was just a fantastic weekend," Rosberg said.
"Everything worked out on Saturday and Sunday. It all came together. I'm very happy and that is it.
"It is seven points (more than Hamilton) and at one point I thought maybe Sebastian can keep Lewis behind, which on one side isn't good for the team, but in terms of my points it would have been better.
"Everyone brought upgrades here but still we're dominating in such a way and that's fantastic to see - more than in the last race."
Hamilton had said after losing out on pole position for the first time this season that he would have to be "fresher" than Rosberg to beat him off the line and lead from the front.
Instead, the 30-year-old suffered wheel spin when the lights went out and was left ruing that moment.
"Obviously I had quite a poor start," Hamilton said.
"It's been a long time since I've had such a poor start. I tried my best to recover.
"Unfortunately, this track isn't very good for overtaking. I did everything I could behind Sebastian and did enough in the first stint but I had a very long pit stop and had to do it all over again."
Vettel may have taken third but he could not do anything about the dominant Silver Arrows - although he does remain in touch with the leaders in the standings.
After his unspectacular start, Hamilton pitted for the first time at the end of lap 14 but a problem with the left rear tyre left him further back - especially when Vettel stopped just a lap later and was three seconds quicker in his box.
The championship leader reeled in the Ferrari of Vettel with some ease, although he failed to pass before taking his second stop on lap 32.
Making great gains on the leading three, Hamilton soon caught and passed Valtteri Bottas and again set off after the Ferrari of Vettel, who ducked into the pits for his second and final stop.
Rosberg's second stop came on lap 45 and he yielded the lead to Hamilton - knowing he would benefit when his rival had to stop again.
That third stop came 15 laps from the end of the race with Hamilton left to chase after his team-mate on a much fresher set of option Pirelli tyres - closing all of the time but being told with eight laps to go that there was little point fighting tooth and nail as any attempt at catching and passing Rosberg would prove futile.
Bottas took fourth place, holding off a late push from Raikkonen, with Williams team-mate Felipe Massa sixth.
Both Red Bulls finished in the points after a disappointing qualifying, with Daniel Ricciardo taking seventh and Daniil Kvyat 10th.