Superb Hamilton reigns in Spain
Lewis Hamilton held off Mercedes team-mate Nico Rosberg over the dying stages of the Spanish Grand Prix to win his fourth successive race.
The gap was just 0.6 seconds between the duelling duo come the chequered flag that dropped after 66 laps, allowing Hamilton to move to the top of the championship for the first time in almost two years.
Daniel Ricciardo finished on the podium for the second time this season, albeit for the first time legitimately after the Australian was disqualified from his home race in March after a fuel irregularity with his Red Bull.
Hamilton now has history on his side because on every one of the 19 previous occasions a driver has won four races in a row in one season he has gone on to claim the world championship.
For Hamilton, this victory will also serve as a crucial psychological blow as it again appeared as if Rosberg had the strategic edge, as in Bahrain last month.
But again Hamilton was able to keep Rosberg at bay, leaving the German to settle for second place for the fourth straight race, with the latter now three points adrift.
On the podium, a clearly relieved Hamilton said: "A big thank you to my team, my first win here in Spain, and it means everything to me.
"Overall, I wasn't fast enough, Nico was quicker, so I had to rely on my engineers a lot more to help me with my settings.
"Fortunately I was able to keep him behind me.''
As for Rosberg, he felt he would have had a shot at Hamilton if there had been one more lap.
Describing himself as "a bit gutted'' at losing his championship lead, Rosberg added: "There are still plenty more races to go.''
Undoubtedly this was not the most entertaining of races, certainly not until the closing laps, but then the Circuit de Catalunya has always been a track where it is difficult to overtake.
It was nonetheless a fascinating intra-team strategy battle between Hamilton and Rosberg, and the body language between them in the green room ahead of the podium spoke volumes as they barely exchanged a word.
From pole position Hamilton knew he had to head into turn one in the lead to give himself the best opportunity of victory, and he produced an unruffled, routine start.
Hamilton did not even have to defend into the opening corner such was his pace off the line, leaving Rosberg instead to fend off Valtteri Bottas as the Finn had charged by Ricciardo into third.
Through the first stint, with both men on the medium-compound tyres, Rosberg was able to keep Hamilton permanently in his sights, ensuring the gap grew no larger than two seconds.
Through the first round of pit stops, with Hamilton in first after 18 laps followed by Rosberg two laps later, the Briton comfortably retained his lead.
The team, however, switched strategies with Rosberg as the German took on the hard Pirelli rubber, whereas Hamilton emerged with a fresh set of mediums.
At that stage, with the gap just over three seconds, Hamilton was told to increase his advantage to six seconds whereas Rosberg was informed to close it to two.
With the cushion down to 2.6secs, Hamilton was heard complaining about oversteer and difficulties with the rear of his car.
From the pitwall, Mercedes offered up suggestions for Hamilton to correct the issues, which appeared to work as by half distance - at 33 laps - he had managed to eke out a lead of 4.4secs.
Behind the runaway duo Ricciardo was running third after passing Bottas in the initial round of stops, but was almost 30 seconds adrift.
Come the second pit stops, with Hamilton taking on the hard tyre after 43 laps and Rosberg the medium again two laps later, it was then game on and a run to the line.
A tetchy Hamilton, however, initially questioned why he had been brought in so early given his pace appeared solid, before asking as to how much time he had lost to Rosberg in the stop.
That resulted in race engineer Pete Bonnington urging Hamilton not to concern himself with such matters and to "knuckle down'' with his own strategy.
From lap 47, though, Rosberg then started to eat into Hamilton's lead as he chopped off 2.6secs in the space of just six laps, cutting the deficit to two seconds.
As they picked through the backmarkers, Rosberg made further gains and by the end of lap 59 the gap was under one second for the first time in the race.
It was then a case of a tenth of a second here and there, but Rosberg never once managed to get close enough to even attempt a pass.
The relief was obvious from Hamilton come the flag, whilst Rosberg's face was one of thunder at times.
Behind them Ricciardo was 49 seconds adrift such is the gap Mercedes have over their rivals, with team-mate Sebastian Vettel a stunning fourth after starting 15th, with Bottas fifth.
Ferrari, winners here last with Fernando Alonso, had to settle for sixth and seventh, with Kimi Raikkonen passed by the Spaniard just over two laps from home.
Romain Grosjean hauled Lotus into the points for the first time in a problematic season, with Force India duo Sergio Perez and Nico Hulkenberg ninth and 10th.
That left McLaren out of the points for the third successive race, with Jenson Button and Kevin Magnussen 11th and 12th, whilst Max Chilton was 19th in his Marussia.