Testing with the DAMS team at Jerez in Spain, Marcus Ericsson ended up with the fastest time of the day in the afternoon, after a morning initially brought to a brief red flag stop because of heavy fog impeding visibility through turns 6 and 7.
The first drivers to set proper laptimes in the first half hour of the morning session were Jolyon Palmer (working with Lotus GP), Stéphane Richelmi (Trident), Ramon Pinero (Ocean Racing Technology) and GP3 champion Mitch Evans (Arden), while the other drivers waited in pit lane for conditions to improve.
With the sun a long time putting in an appearance, the drivers were gradually coaxed to come out and play despite the still-tricky conditions. Ericsson took to the top of the timesheets with his DAMS colleague Rio Haryanto dutifully slotting into second place around seven tenths of a second further back.
Ericsson was finally displaced from the top of the timesheets by Felipe Nasr in the Carlin putting in a lap of 1:26.810s thirty minutes before the lunchtime break, and a flurry of better laps in the improving midday conditions saw 2. Stéphane Richelmi (Trident Racing) and Stefano Coletti (Rapax) also go faster than the Swede before the chequered flag came out.
Sunshine greeted the teams and drivers for the start of the afternoon session, with Stefano Coletti setting the initial pace in the Rapax ahead of Venezuela GP Lazarus' Kevin Giovesi, and Marcus Ericsson again quick off the block in third place in the first 30 minutes.
With the conditions now the best that they had been all day, the drivers were keen to get as much running as they could over the next two hours. By the midpoint of the afternoon session, Johnny Cecotto Jr. was on top of the times followed by Racing Engineering's Nigel Melker and former GP3 Series driver Alexander Sims, here working with Barwa Addax.
Nasr bean his team mate for the day's time to go top before the hour-to-go mark as the skies started to grow dark and overcast again, and with 30 minutes remaining it was Ericsson back in charge with what proved to be the best lap of the day with a time of 1:26.717s which put him 0.166s ahead of Sims, Giovesi, Richelmi and Fabio Onidi (Coloni), who had just pipped Cecotto for sixth place on the time screens.
The session ended on time, having avoided any further red flags other than the early one for foggy conditions.
The second day of testing will start at 9am local time (8am GMT). Barwa Addax, Rapax and Caterham plan unchanged driver line-ups, while DAMS will be represented by Richelmi and Mitch Evans; Racing Engineering by Melker and Fabio Leimer; iSport by Palmer and Kevin Mirocha; Trident by Sergio Canamasas and Julian Leal; Lotus GP with Haryanto and Daniel Abt; Venezuela GP Lazarus by Giovesi and Rene Binder; and Arden with Cecotto and Adrian Quaife-Hobbs. Ramon Pinero sticks with Ocean, and Felipe Nasr will stay with Carlin.
"The car felt really good today and we were lit up as soon as we hit the track this morning so we were able to go onto new tyres straight away," he said of his work on Thursday. "In the afternoon we were working on the car and our programme. I've felt really comfortable and I know the team really well so it makes everything easier – we've definitely made a progress."
It will be the final session of the year for the GP2 teams and drivers, and the final day of involvement for Scuderia Coloni, which quits the series at the end of 2012. Colini's final outing will be fronted by Ericsson and Daniël de Jong.
Full day 1 testing times