Mark Webber clocked the best time of the day at a rain-swept Barcelona as the final pre-season test of the winter endured a soggy start on Thursday.
The Red Bull driver posted a 1min 22.693 lap in the afternoon session after the morning action saw drivers tentatively tackle a Catalunya circuit made treacherous by heavy rain.
Webber's best time was set on the soft tyres, with 2008 world champion Lewis Hamilton second quickest for Mercedes in 1min24.348 - a yawning gap of 1.655 seconds - on medium tyres.
“We got one hour at the end of the day at half-sensible conditions and we had a look at a few different compounds,” Webber told Sky Sports television, who also claimed a Formula One first by broadcasting the session live in 3D in Britain.
“We opted to throw on some tyres and see how the car went, and that went okay,” he added after completing 90 laps of the Circuit de Catalunya at Montmeló.
“We've still got work to do.”
“We are seeing some very fast times from the other cars. There are some very strong teams out there. We're not on our own, that's for sure.”
Former World champion Lewis Hamilton had been quickest in the morning but even his 1min 41.614, off a modest total of 43 laps in his Mercedes, was a long way off the times set at the same circuit last week.
Hamilton eventually put in 113 laps, the most of any driver and improved his time to 1min 24.348 with France's Jean-Eric Vergne, in a Toro Rosso, the third fastest in 1:25.017.
Hamilton has now completed 2,040km over five days of winter testing, equivalent to nearly seven Grand Prix distances.
he said: “The track started out really wet this morning but thankfully the conditions dried out later on and we were able to complete some proper running.
“It felt good to work through the race simulation this afternoon, both to get myself back in practice and to put valuable miles on the car. All the guys have done a fantastic job both here and at the factory.
“I'm really happy that we're making progress together and very much enjoying working with everybody.”
SECOND CHANCE FOR SUTIL
Meanwhile, Force India confirmed Adrian Sutil as one of their drivers for the new Formula One season, signalling a return for the German after a 12-month absence.
Sutil and Paul di Resta will now be the team's drivers for the 2013 Grand Prix season, as they were in 2011.
Confirmation of the driver line-up came after Sutil saw off competition for the second Force India berth from reserve driver Jules Bianchi, with the French rookie's agent saying in Paris on Wednesday his client had lost out.
Sutil, 30, drove for Spyker, as the team was then known, and Force India from 2007 to 2011. He competed in 90 Grands Prix and achieved a best result of fourth at the Italian Grand Prix in Monza in 2009.
But he lost his Force India drive in 2012 after a conviction for assaulting the co-owner of the Lotus team, Eric Lux, in a Shanghai bar following the 2011 Chinese GP.
Sutil said: “I'm delighted to be back in Formula One, especially with a team I know so well.”
Winter testing will conclude on Saturday ahead of the season's opening Grand Prix in Australia on March 17. - AFP, Reuters
1 Mark Webber (Australia) Red Bull - 1min22.693 (90 laps)
2 Lewis Hamilton (Britain) Mercedes - 1min24.348 (113)
3 Jean-Eric Vergne (France) Toro Rosso - 1min25.017 (59)
4 Valtteri Bottas (Finland) Williams - 1min26.458 (85)
5 Sergio Perez (Mexico) McLaren - 1min26.538 (100)
6 Esteban Gutierrez (Mexico) Sauber - Ferrari - 1min26.574 (92)
7 Paul di Resta (Britain) Force India - 1min27.107 (57)
8 Felipe Massa (Brazil) Ferrari - 1min27.541 (112)
9 Max Chilton (Britain) Marussia - 1min28.166 (78)
10 Charles Pic (France) Caterham - 1min28.644 (83)
11 Romain Grosjean (France) Lotus - 1min34.928 (52)