The win also set a record, one that Hamilton had previously shared with seven times champion Michael Schumacher, of 41 wins from pole position.
Lewis Hamilton won the Spanish Grand Prix in a commanding Mercedes one-two on Sunday to stretch his Formula One lead over Ferrari's Sebastian Vettel, who finished fourth, to 17 points.
The victory, in a race that stayed dry despite the threat of rain, was the Briton's second of the season, 64th of his career and third at the Circuit de Catalunya.
It also set a record, one that Hamilton had previously shared with seven times champion Michael Schumacher, of 41 wins from pole position.
Finland's Valtteri Bottas was second, a hefty 20.5 seconds behind, with Dutch 20-year-old Max Verstappen completing the podium for Red Bull -- his first of an incident-filled season.
"This is more like it, let's keep this up," Hamilton told his celebrating team over the radio as he swept past the chequered flag.
"Today the car and myself, I felt that synergy which I hadn't been feeling for the whole year," he added in a pre-podium interview after parking up in pit lane.
"It's a good feeling."
Hamilton's win followed on from the lucky victory that fell into his lap in Azerbaijan two weekends ago, but Sunday had nothing to do with chance and all to do with the champions being back to their best.
He now has 95 points to Vettel's 78 after five rounds of the 21-race championship.
Mercedes regained the lead in the constructors' standings and are now 27 points clear of Ferrari who had 2007 world champion Kimi Raikkonen retire from the race.
Australian Daniel Ricciardo was fifth for Red Bull, ahead of Denmark's Kevin Magnussen for Haas and Spaniards Carlos Sainz (Renault) and Fernando Alonso (eighth for McLaren).
Sainz's points lifted Renault ahead of McLaren and into fourth place by a single point.
Mexican Sergio Perez was ninth for Force India and Monegasque rookie Charles Leclerc took the final point for Sauber.
While Hamilton pulled away cleanly at the start, and Vettel passed Bottas into the first corner for second place, there was carnage behind as Romain Grosjean spun his Haas in a cloud of smoke.
The Frenchman then collected the Renault of Nico Hulkenberg and Pierre Gasly's Toro Rosso in a major smash, fortunately without injury, that brought out the safety car for the first six laps.
Stewards gave him two penalty points and imposed a three-place grid drop for the next race in Monaco.
When racing resumed Vettel was first of the leading group to pit but the Mercedes pair stayed out on what turned out to be a one-stop strategy, with Hamilton immediately smashing the lap record.
When Vettel made his second stop during a late virtual safety car period, after Esteban Ocon parked up his Force India by the side of the track, it backfired and he lost places instead of gaining anything.
"We couldn't make the tyres last," said Vettel. "I think it was the right thing to do.
"Even in the end, with the fresher set, I wasn't able to attack," he added.
Verstappen, whose season has been littered with collisions, also nearly wrecked his race when he hit the rear of Canadian Lance Stroll's Williams and lost a front wing end-plate.
"Feels nice to be on the podium and nice to have a good clean race," said Verstappen.