With a faultless and unchallenged 64th victory, the British driver extended his championship lead over Ferrari's Sebastian Vettel to 17 points and, more importantly, the Mercedes cars appear to have a comfortable pace advantage again. Hamilton won nine races to Bottas's three in 2017. Team boss Toto Wolff said the team's focus had been on beating Ferrari over the past month and would switch to contract talks when a better opportunity arises. Hamilton was joined on the podium in Spain by Mercedes team-mate Valtteri Bottas and Red Bull's Max Verstappen.
Hamilton is now standing at the top spot in the drivers' championship, maintaining a lead of just four points over Vettel. After that I was really surprised they didn't have the pace to keep up with me.
"Obviously normally you don't get the chance to revisit this kind of decisions that are made, but I think we did now with the day that we had today, and I think the result is that, if we had the normal tyres on Sunday, we'd probably even be worse off". "It's a good feeling".
It is a sign of how well Hamilton is driving in Barcelona that fellow four-time champion Vettel, not far from his own best, still could not overhaul him.
Hamilton and the rest of Mercedes-AMG made their mark as early as qualifying. "The first run was not so good, but the last lap I was happy", he said.
He said "Before I was like, "Maybe I'm just insane and everyone has got quicker and I've got slower". He has some serious records.More news: Fonseca holds West Ham talks at Sullivan home
"It's going to be hard". Seventeen championship points is a healthy cushion, but Hamilton may very well need it if he suffers another horror show in the principality.
"But [I have] the will to want to get this one and do it right, flawless weekend in, weekend out". "I would like to hope it could be part of the turning point".
Haas' Kevin Magnussen was over 1.5 seconds down on Hamilton, finishing narrowly ahead of home favourite Fernando Alonso as McLaren enjoyed a more positive outing. Sergio Perez finished in ninth place ahead of the Sauber of Charles Leclerc.
Hamilton had a clean start, with Vettel moving from third to second by passing Bottas on the outside of Turn 1.
"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". He lost time in the pits and came back onto the track behind Verstappen, and was unable to make up the difference despite the newer tyres.
"I think it's pretty straightforward", he said. "I think it will be an interesting race".