Sebastian Vettel secured his fourth victory from five races in 2011 despite Lewis Hamilton stalking the Red Bull driver for the entire race.
Vettel – who now has 118 points from a maximum 125 – crossed the line only 0.630 seconds ahead of the McLaren driver after 66 laps of the Spanish track. The close race was all the more remarkable considering the Red Bull was eight-tenths quicker than its rivals per lap in Saturday qualifying.
McLaren’s Jenson Button joined Vettel and Hamilton on the podium after effectively using a three-stop strategy. Mark Webber and Ferrari’s Fernando Alonso were fourth and fifth but crucially stopped once more than the Englishman.
The Spaniard will leave Barcelona disappointed finishing a lap down having led the race for the first 20 laps.
Alonso starting from fourth passed both Red Bulls and Hamilton on the long run down to turn one after a blistering getaway and fully utilising his KERS system.
Pole sitter Webber was also passed by his team-mate and settled into third ahead of Hamilton.
Button however had a miserable start and a mixture of wheel-spin and over caution on the opening lap left him down in tenth and battling with the Toro Rosso of Sebastien Buemi.
Vettel said: “At the beginning of the race I had a good start but I don’t understand where Fernando Alonso came from.”
Alonso, who had been over a second off the pace all weekend, was largely untroubled out in front as Vettel, without a fully functioning KERS, could not pass the Ferrari even using DRS.
Using the soft tyres from qualifying the front-runners pitted on between laps 10 and 12. Hamilton, the last of the leaders to pit, overtook Webber to take third.
Seven laps later and Vettel sparked the second round of stops and got the jump on Alonso who stopped on lap 20. Once again Hamilton stayed out longer and also made his way past the Spaniard – but four seconds behind the world champion.
For the remainder of the race Hamilton slowly closed onto the back of the Red Bull but even with KERS and DRS advantages he was unable to force his way past.
Button battled his way past Webber and then Alonso to take third on laps 36 and 37 while on the faster option tyre.
The Australian himself managed to pass Alonso during the fourth round of pit-stops to take a disappointing fourth.
“It was an interesting day today and it goes to show you how fine the margins are when you are off a little bit on strategy,” he said.
“If you can’t clear people at the right time, you get exposed. At certain stages I was quick, other stages I wasn’t.”
Alonso was equally sombre after the race. The Spaniard – who has just signed a new five-year with the team – said: “It looks a little bit sad when you lose positions but we must understand that P1 is not our position at the moment.”
“We were not competitive at raw pace, we were too slow with hard tyre. There are clearly two teams ahead of everybody and at the moment we need to change the situation.”
The Mercedes pair of Michael Schumacher and Nico Rosberg had uneventful races to finish sixth and seventh and cement their position as F1’s fourth team ahead of Renault.
The seven-time world champion said: “We got the maximum with what we had available. I don’t know what was going wrong but definitely we lost out on performance for today compared to what we had Friday.”
Nick Heidfeld completed a fantastic drive from last on the grid to eighth and the Sauber pair of Sergio Perez and Kamui Kobayashi completed the top-ten.
But it was a frustrating day for Felipe Massa who retired with a gearbox problem while running tenth and for Heikki Kovalainen who crashed late on as the Lotus team failed to match their qualifying showing.