Lewis Hamilton laid down an impressive marker ahead of the new Formula One season on Saturday when he set the best time on the third day of testing, his Mercedes thriving in the dry conditions.
The 2008 world champion, who had also set the benchmark in Thursday's opening session, clocked 1min 20.558sec, beating the fastest time of 1min 21.848sec in last month's four-day test at the same circuit set by McLaren's Sergio Perez.
Driving on super-soft tyres, Hamilton was the only man to dip below 1min 21sec with Ferrari's Felipe Massa taking second place ahead of Force India's Adrian Sutil.
"It was great to have a dry track today for my final day of testing, and we were able to get through all the test items that we wanted to achieve by the end of my programme," said Hamilton.
"There's still a lot of work ahead of us to get to where we want to be but the team is doing a great job.
"The reliability, the mileage and the step-by-step improvements that we have achieved during the three tests are all very encouraging."
Despite his blistering pace on Saturday, Hamilton insisted he would not be getting carried away by the performance of the Mercedes, cautious of rivals Red Bull and Ferrari still yet to show their hand.
"Whilst we've been focusing on our own performance, we definitely haven't seen the full potential of our competitors yet, so it's difficult to predict where we might be," said the Briton.
Elsewhere Saturday, Italian driver Davide Valsecchi stepped up from his reserve role with Lotus to make his debut when former world champion Kimi Raikkonen opted out of the session through illness.
Valsecchi, the second-tier GP2 world champion last season, was only informed of his surprise opportunity at just before 9 o'clock this morning.
He managed only 16 laps in the morning session before passing the driving duties to Romain Grosjean, who had set the best time on Friday.
"I certainly didn't expect to be in the car again today so it was an interruption to a day off, but as interruptions go it was a pretty good one," said Grosjean.
"I hope that Kimi is feeling better for tomorrow, but I don't mind driving again if I have to."
Sunday will be the last day of winter testing and will feature triple world champion Sebastian Vettel in the Red Bull and former double champion Fernando Alonso in the Ferrari.
The new season starts in Melbourne on March 17.
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