The Frenchman waited until there was less than 30 minutes remaining for the day before he set the benchmark time of 1m23.252s, using a set of Pirelli's soft tyres to eclipse Jenson Button's fastest time from the morning's session.

Faster times were a rarity in the afternoon sessions, with teams opting to use the stable track conditions to go for longer runs. Grosjean was one of only two drivers to improve after lunch, the other being Red Bull Racing's Mark Webber.

However, Webber was only able to shave a tenth off his best morning time, leaving him behind Button and Perez - both with morning times – in fourth for the day.

Behind Webber it was Nico Rosberg, the Mercedes driver the busiest of the day with 128 laps for the day, mostly completed over long stints. Jean-Eric Vergne was sixth fastest, with Toro Rosso dedicating much of the last hour to pitstop practice.

Felipe Massa had a busy afternoon, eventually completing 105 laps for the day, despite a lengthy stay in the pits after lunch. However, his best time was only good enough for eighth.

Vitaly Petrov, subbing for the ill Heikki Kovalainen, was the second busiest man of the day, putting the new Caterham through 123 laps.

His reward was avoiding the bottom of the time sheets, with Petrov ending the day 0.711s clear of Pastor Maldonado, the Williams driver completing the least number of laps for the day with just 58.

Testing resumes tomorrow at Barcelona.

Today's times

Pos  Driver         Team            Time                Laps
 1.  Grosjean       Lotus           1m23.252s           73
 2.  Button         McLaren         1m23.510s  +0.258   64
 3.  Perez          Sauber          1m23.820s  +0.568   118
 4.  Webber         Red Bull        1m23.830s  +0.578   102
 5.  Rosberg        Mercedes        1m23.992s  +0.740   128
 6.  Vergne         Toro Rosso      1m24.216s  +0.964   113
 7.  Di Resta       Force India     1m24.305s  +1.053   98
 8.  Massa          Ferrari         1m24.318s  +1.066   105
 9.  Petrov         Caterham        1m24.876s  +1.624   123
10.  Maldonado      Williams        1m25.587s  +2.335   58

Autosport.com