After winning by just a few car lengths, or 0.6ec, at the Circuit de Catalunya, Hamilton said Rosberg had been the faster driver, but he had won thanks to advice from his race team in the closing stages of a dramatic race.
“A big thank you for my team,” he said, as he sat on the podium afterwards.
“They have done an incredible job this year and the support here (in Spain) is the best I have ever had and my first win in Spain means everything to me.”
Asked about his frequent questions for his race team, he said: “I was not upset, but I was not fast enough today. Nico was quicker. I struggled with the balance and needed to rely on my engineers.
“I was moving my settings up and down and fortunately I was able to keep Nico behind.”
In a heart-stopping conclusion to an intriguing 66-laps race, Hamilton resisted the pressure from Rosberg to finish just 0.6sec ahead.
His victory lifted him to 100 points for the season and into the lead of the title race ahead of Rosberg, on 97.
Australian Daniel Ricciardo came home third for Red Bull ahead of his team-mate defending four time world champion German Sebastian Vettel, who had started from 15th on the grid.
For Ricciardo it was a moment of special satisfaction to claim his first Formula One podium, having done so in the season-opening Australian Grand Prix before being disqualified for a fuel irregularity.
- ‘A bit gutted’ -
Rosberg, after finishing second behind Hamilton for the fourth consecutive time, said he felt he needed just one more lap to make a passing move on his team-mate.
“I think one more lap and I could have given it a good go!” he said. “Unfortunately that was it and I am a bit gutted, but still, second place, second in the championship and many more races to go… I will go to Monaco to go one better and try and repeat the win from last year.”
A beaming Ricciardo, who finished 49sec behind Hamilton, said: “We did not have the pace on Mercedes. We had a pretty comfortable third place and it is really nice to be on the podium and I am sure I will get to keep it this time!”
It was Hamilton’s fourth win this year, his first in Spain and the 26th of his career while Mercedes one-two stamped their complete supremacy on the constructors’ championship which they now lead by more than 100 points.
Finn Valtteri Bottas finished fifth for the resurgent Williams team ahead of local hero and two-time champion Spaniard Fernando Alonso and his Ferrari team-mate 2007 champion Finn Kimi Raikkonen.
Frenchman Romain Grosjean was eighth for Lotus, signaling their return to some form after a dismal start to the year, ahead of Mexican Sergio Perez and his Force India team-mate German Nico Hulkenberg, who was 10th.
Hamilton added that he had not dared dream of such a strong start to his second season with Mercedes after his unexpected decision to leave McLaren.
“Sitting down with Ross (Brawn) in my mum’s house,” he recalled.
“This is what the idea was, that I was given. I wasn’t sure we could actually be a second faster than Red Bull, but we’ve managed to do it. I’m really pleased and to have our fourth 1-2 finish together is unreal.”
Hamilton now has a 55-point lead over fourth-placed Vettel, whose strong drive after two days blighted by setbacks signalled his threat.
Vettel said: “That was more fun than the last race when I had to let people by. All in all it was the maximum we could do.”
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