The team did an exceptional job.
"We do after the five races now have a much, much better understanding of the vehicle, of what we need to do to get the auto to be working - but we still have learning to do, improvements to be made.
That said, I will sleep like a baby tonight". "I think it was the right thing to do", said Vettel.
He had won in Bahrain and in the season-opener in Australia, when he wasn't as dominant as Hamilton but took advantage of a safety auto to win on race strategy.
Vettel, who now trails Hamilton by 17 points in the drivers' standings, was only fourth after a change in strategy didn't pay off. Bottas had done enough on track to move back ahead of the Ferrari only for a sticky rear tyre to contribute to a slow stop and leave Vettel running ahead.
Hamilton now has 95 points to Vettel's 78 after five rounds of the 21-race championship. Alonso often starts well in Spain, and as the only driver on super-softs he should get a better launch from the line than the rest of the top ten.
"I'm really, really happy", said Hamilton. Mercedes have not been able to get the most from their auto since the opening round in Melbourne and have been repeatedly out-paced by Ferrari. It has been a constant learning process with the tyres, getting them working in a very narrow window. This is hard to cope with and in the following races we struggled and all that adds up and was in all our minds.
"Everything we put on the vehicle seems to work and that's important", Vettel said. "We were going through the tyres too quick and therefore we were not able to stay out for another 23 laps".
"I'm almost in the groove", he added.
INSTAGRAM MERCEDES Lewis Hamilton loves the Silver Arrows team so much his garage is crammed with Mercs
The lack of performance from Ferrari would be alarming. On the mediums, his Ferrari could manage only half of the number of laps (24) as Bottas (47).
The victory comes one race after his triumph in the Azerbaijan Grand Prix.
One of the leading lights of last year's championship, Esteban Ocon has yet replicate his 2017 form and continues to drop further behind his team-mate Sergio Perez. "We had to stop again and we obviously lost two positions, and also a bit of time during the pit stop itself".
The other issue for Ferrari was their unreliability. Kimi Raikkonen finished in fourth place for Ferrari. The rain threatened to return, with clouds hanging darker than the Catalan tarmac, and with the four race strong streak of safety cars both virtual and real, a monkey wrench looked certain to be thrown into the race's proceedings. Daniel Ricciardo (Red Bull) + 50.058; 6. Live the race in Barcelona will show the channel "First Car".
Verstappen then hit back of Sirotkin, but despite sustaining damage to his front wing, held off Vettel with relative ease. Ricciardo was eventually called in on lap 34, with Verstappen pitting a lap later.
Verstappen, whose season has been littered with collisions, also almost wrecked his race when he hit the rear of Canadian Lance Stroll's Williams and lost a front wing end-plate.
"To think that is my 64th, it still feels like a first, special and unique in its own way", he added.
"We definitely go to Monaco on a high note, but we know that we still have a lot of work to do".
Cleanup required a safety vehicle, extending the streak of safety auto (or virtual safety car) appearances to five this season.More news: Las Vegas evens Stanley Cup series with Winnipeg
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