Lewis Hamilton labelled his Spanish Grand Prix weekend a "hiccup" after he lost out to Mercedes team-mate Nico Rosberg for the first time this season.

Having won three of the opening four races and started all of them from pole, reigning champion Hamilton had to watch Rosberg take victory from the front - but still fought back from a poor start and a delayed pit-stop to finish second.

That means he heads to Monaco with a 20-point lead over Rosberg with the Ferrari of Sebastian Vettel finishing third at the Circuit de Catalunya to remain the best of the rest.

Hamilton has not won on the streets of the principality since his title-winning season of 2008 but will not be worried that his dominance may now be tested after a relatively disappointing weekend.

"This is just a hiccup, I guess, this weekend," he said.

"I just clearly got a bad start. I had lots of wheel-spin. This was a difficult weekend for me, I'll definitely take it (finishing second) and I'm looking forward to Monaco.

"I think I pushed until there were six laps to go and I still had 13 seconds to go (to catch Rosberg) so after that I kind of realised that I should bring the car home and live to fight another day."

Rosberg took the chequered flag for the first time since the Brazilian Grand Prix in November.

"It was just a fantastic weekend," he said.

"Everything worked out on Saturday and Sunday. It all came together. I'm very happy and that is it.

"It is seven points (more than Hamilton) and at one point I thought maybe Sebastian can keep Lewis behind, which on one side isn't good for the team, but in terms of my points it would have been better.

"Everyone brought upgrades here but still we're dominating in such a way and that's fantastic to see - more than in the last race."

Vettel finished a distant third and is now 31 points adrift of Hamilton in the standings but, despite the clear speed advantage of the Mercedes, the four-time world champion still believes he is in the hunt this year.

"I think I'm in the fight," he said.

"We are able to improve our car - I think there are some good steps coming.

"Obviously our opponent is favourite for the whole year and was untouchable last year to be fair, so I think the way you need to look at it is not that Mercedes is so strong, the way you need to look at it is that Ferrari was able to close the gap more than anyone else."