McLaren’s Sergio Perez was top of the timesheet as he finished his two days of running in the second pre-season Formula One test.
Perez, who will make way for his team-mate Jenson Button for the final two days at Barcelona's Circuit de Catalunya this week, posted an impressive lap of one minute 21.818 seconds.
However, Perez's time was set on the much quicker soft compound of Pirelli tyres compared to those behind him in the standings today.
But it at least compared favourably to Lewis Hamilton’s 1min 21.707secs that was good enough for pole in last year's Spanish Grand when he was with McLaren, prior to being dumped to the back of the grid for a fuel irregularity.
Pirelli are also at least proving themselves to be as good as their word for this season as they promised their compounds would be 0.5s per lap quicker than those from last year.
The best time on soft tyres over the eight days of testing at Barcelona 12 months ago was 1:22.312.
It is expected that Perez's time will be bettered over the remaining six days at the track, two this week and a further four at the tail end of next week.
Behind the 23-year-old was Sebastian Vettel, the current triple world champion 0.349 adrift in his Red Bull, with the German also now finished for the week as he will hand over the reins of the RB9 to Mark Webber.
Vettel brought out one of two red flags for the day when he stopped at the end of the pit straight with what was understood to be a loose wheel nut following a practice pit stop.
The German's problems, however, paled into insignificance compared to those of Kimi Raikkonen as the Finn was unable to set a time in his Lotus until 90 minutes from the end of the session due to a gearbox change.
Raikkonen was half a second down on Vettel, with both men on the medium compound of tyre.
However, Mercedes' Hamilton produced arguably the most impressive time of the day, and he also racked up 121 laps, almost double the race distance for the Spanish Grand Prix.
Although Hamilton finished 0.9 behind Perez, his best lap of 1:22.726 was set on the hard tyres, and will probably have impressed many of his rivals.
Fernando Alonso, on the second of his three successive days behind the wheel of his Ferrari, was 1.399 down on Perez.
Valtteri Bottas, on his maiden outing in the new Williams FW35 that was unveiled yesterday, finished a further 0.314 adrift of Alonso.
Toro Rosso's Daniel Ricciardo was seventh quickest, followed by Paul Di Resta in his Force India, the Scot 2.123 off the pace, ahead of former team-mate Nico Hulkenberg, now driving for Sauber.
The bottom two, and again lagging behind, were Marussia's Max Chilton and Charles Pic in his Caterham, 3.267 and 4.395 adrift respectively.