Three-time defending world champion Sebastian Vettel recorded the quickest time in Jerez, Spain on Friday morning on the fourth and final day of testing ahead of the 2013 Formula One season.
Vettel, in the new Red Bull RB9 car, was just ahead of Mexico's Esteban Gutierrez in a Sauber.
Gutierrez will make his Formula One debut at the Australian Grand Prix in Melbourne on March 17.
Lewis Hamilton was third-quickest in his Mercedes, while Spain's Pedro De La Rosa made an inauspicious first appearance in a Ferrari.
He was forced to call a halt to his morning's testing on just his second lap because of a gearbox problem.