Felipe Massa set the fastest time on a disjointed opening day of testing at Silverstone.
In cool conditions, Massa set a best time of 1:35.242 on the medium tyre in the morning session to beat Daniel Ricciardo by a mere 0.006s. Massa completed just 42 laps throughout the day but Williams completed its program in good time to allow Massa to conclude his running with more than half an hour of track time available.
Ricciardo had a slow start to the day as he failed to set a time in the opening four hours but improved in the final 30 minutes to a best of 1:35.248, managing 72 laps in total. Rosberg's day was more productive as he completed 90 laps and set a best time of 1:35.573, while Adrian Sutil also completed more than a race distance and finished the day within half a second of Massa in fourth place.
It was Jules Bianchi in fifth – testing tyres for Pirelli – who had the highest total as he managed 108 laps before a small fire caused him to stop on track and ended the team's running prematurely. Marussia said the damage would not impact on Wednesday's running for Max Chilton but that there was “some clearing up to do”.
Stoffel Vandoorne was sixth fastest for McLaren on his second appearance for the team this season, setting a best time of 1:36.462, which left him 0.1s clear of Sergio Perez in the Force India.
Jean-Eric Vergne ended the day eighth on the timesheets but was the cause of no fewer than three red flags as he completed just 28 laps for Toro Rosso on a tough day for the team. By contrast, Pastor Maldonado managed 97 laps but was 1.8s off the ultimate pace.
Pedro de la Rosa was driving for Ferrari and carrying out tyre testing duties for Pirelli, but failed to reach the 50-lap mark and was almost a second slower than Maldonado ahead of him, while Will Stevens was slowest and over five seconds off the overall pace.