Barcelona FP1: Mercedes on top as Rosberg goes fastest

Three weeks since the last grand prix and little has changed at the top of the Formula 1 pecking order as Mercedes once again set the pace in the first free practice session of the Spanish Grand Prix weekend with Ferrari stalking them and the rest chasing.

Nico Rosberg boosted his morale by keeping Mercedes team mate and championship leader Lewis Hamilton off the top of the timesheets in first practice at Circuit de Catalunya-Barcelona.

Rosberg set a best lap of 1:26.828, 0.070 of a second quicker than Hamilton, on a sunny morning at the Circuit de Catalunya as the sport kicked off its first European weekend of the season.

Hamilton, last year's winner in Spain, has won three of four races this season and started all on pole. He leads Rosberg by 27 points.

Ferrari's Sebastian Vettel was third fastest, but with a time of 1:27.806, a second off the top time, which underlined the gap to make up on Mercedes, with team mate Kimi Raikkonen fourth in a predictable looking leaderboard.

Toro Rosso's rookie pairing of Carlos Sainz, making his home debut, and Max Verstappen were fifth and sixth respectively but he junior Red Bull team eclipsed the main squad who endured another difficult morning with Australian Daniel Ricciardo sidelined for much of the session.

Daniil Kvyat setting the morning’s sixth-fastest lap with a time of 1:28.785, almost two seconds down on Rosberg’s P1 time.

The Russian ran a new nose on his RB11 but with the team facing continuing engine issues both he and team-mate Daniel put in limited running, with Kvyat logging just seven laps and Ricciardo, who finished ninth, posting nine.

The bulk of Ricciardo’s running was done late in the session as after just a single lap early in the 90 minutes he had reported a problem when he applied full throttle. The issue restricted him to the garage then until the final ten minutes of running.

Susie Wolff made the third Friday practice appearance of her career with Williams, 40 years on from the only occasion on which a woman driver - Lella Lombardi - has finished in the points, and ended up with a faster time than two world champions.

The Scot, who is married to Mercedes motorsport head Toto Wolff, will not race on Sunday but was 14th fastest and ahead of McLaren's Fernando Alonso and Jenson Button -- 15th and 16th respectively.

Wolff's best of 1:29.708 compared to Williams' race driver Felipe Massa's 1:28.831, although Wolff was carrying out a set programme with outright speed not the main focus.

Nico Hulkenberg slotted into P11 and the Force India driver ahead of Ferrari academy driver Raffaele Marciello, standing in for Sauber’s Marcus Ericsson setting a time of 1:29.630 to finish 2.6 seconds off Rosberg.

He was followed by Jolyon Palmer who replaced Romain Grosjean in the Lotus for FP1.

The lower end of the order saw the upgraded McLarens of Fernando Alonso and Jenson Button finish 15th and 16th respectively.

Sergio Perez was 17th ahead of Lotus’ Pastor Maldonado and the twin Manor cars of Will Stevens and Roberto Merhi.

[highlight ]Spanish Grand Prix, Free Practice 1 - Friday, 8 May 2015[/highlight]