Nico Rosberg on Top in Second Practice of Spanish Grand Prix

Nico Rosberg's golden run continued unbroken on Friday when he topped the times ahead of Ferrari's Kimi Raikkonen and his Mercedes team-mate Lewis Hamilton in second free practice session for this weekend's Spanish Grand Prix.

The 30-year-old German leader of this year's title race, who is 43 points ahead of defending three-time champion Hamilton, clocked a best lap in one minute and 23.922 seconds.

This enabled him to outpace Finn Raikkonen by 0.254 seconds and Hamilton by seven-tenths, ample proof that he has the pace and edge to extend his winning sequence to five races this year and eight in all in Sunday's contest at the Circuit de Catalunya.

"It's great to be back in Europe and to be back in Spain," said Rosberg. "It was a good start for us today with two good sessions. Times were looking good on the long run and also on the shorter stints.

"I feel very comfortable with the car, with some new parts added, and they seemed to have worked well. Ferrari also looked very strong around this circuit so I'm looking forward to Saturday's third practice as well as qualifying and to see how we perform."

Rosberg's confidence was as clear as Hamilton's hesitancy on a day that supplied, as expected, a continuation of this year's form to date.

"That wasn't an easy day for me," said Hamilton. "I struggled with the car balance throughout the day -- and this afternoon, in particular, it felt really tricky to drive.

"I had traffic on my quick lap, so the lap times don't tell the full story, but it's clear we have plenty of work to do this evening to get the car driving like I want it to.

"But we will get our heads down this evening and work through the data -- and I'm confident we can pull things around for tomorrow."

'Tricky' for Vettel

Rosberg had been third-fastest in the morning, half a second behind the two Ferraris led by Raikkonen's team-mate, four-time champion Sebastian Vettel.

That saw the two Ferraris head the Mercedes men and the two Red Bulls with Australian Daniel Ricciardo leading an impressive Max Verstappen in fifth and sixth places, an effort the Dutch teenager almost reprised in the second session.

Vettel was down to fourth in the afternoon ahead of a resurgent and inspired Spaniard Carlos Sainz of Toro Rosso, Ricciardo and local hero, two-time champion Fernando Alonso of McLaren.

They all improved to push Verstappen down into eighth in the second Red Bull ahead of the two Force Indias of Mexican Sergio Perez and German Nico Hulkenberg.

"I think this afternoon was a bit more tricky," said Vettel. "Not as good as the morning, but I think still we can work on the car and improve overnight. We are strong at doing that.

"Even if today was not the perfect day, I think it should be ok."

Verstappen was satisfied with his runs to sixth and eighth.

"I think I can be happy," he said. "I did all the procedures, I was enjoying it. I was getting used to the car still, but it was all going very positive."

Russian Daniil Kvyat, demoted to Toro Rosso to make room at Red Bull for Dutchman Verstappen, struggled to 15th place.

But, on a day when 10 drivers from Vettel to 13th-placed Frenchman Romain Grosjean of Haas, clocked tightly-packed times in the 1min 25sec's, it was barely of great significance.

Rosberg was, as Vettel had been in the morning, the only driver to dip under the 1:24 barrier in the afternoon with Raikkonen and Hamilton in close pursuit -- a scenario that means Hamilton needs to make a quantum leap overnight if he is to close the gap in Saturday's qualifying session.