Feb 28 Mark Webber was fastest for champions Red Bull in Formula One testing in Barcelona on Thursday with the Australian becoming the ninth driver to top the timesheets in as many test days so far this year.
The opening day of the final test at the Spanish circuit before the season starts in Melbourne on March 17 started cold and wet but ended brightly with Red Bull finally setting the pace for the first time in 2013.
Webber's best time of one minute 22.693 was set on the soft tyres, with 2008 world champion Lewis Hamilton second quickest for Mercedes in 1:24.348 - 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.
"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."
Frenchman Jean-Eric Vergne was third quickest, although the times mean little given that teams are trying out different settings with various fuel loads, for Toro Rosso while Valtteri Bottas was fourth for Williams.
"It's a shame we were disrupted a bit by the wet weather, although this did allow us to run on the wet, intermediate and dry tyres," said the Finn.
Hamilton's 113 laps were the most by any driver.
More rain is forecast for Friday before better, drier weather at the weekend. The test ends on Sunday. (Reporting by Alan Baldwin, editing by John Mehaffey)