Sepang, Malaysia - Lewis Hamilton turned the tables on world championship leader Nico Rosberg, giving himself a badly-needed boost with the fastest lap in second free practice Friday for the Malaysian Grand Prix.
Rosberg has been in dominant form over the past three races, winning them all to turn a 19-point deficit into an eight-point lead in the title race.
But his Mercedes team-mate and the reigning world champion Hamilton returned to top form with a lap of the 5.543km Sepang circuit in 1min 34.944sec on his soft-tyre qualifying simulation run, 0.244sec quicker than the German.
With the sun heating the newly-laid track to a blistering 58 degrees Celsius (136 Fahrenheit), Hamilton proved most adept at getting the best from his tyres in the harsh conditions.
After losing more than half of his set-up time to mechanical problems in practice two weeks ago in Singapore, Hamilton was delighted to get two flawless sessions under his belt on Friday.
"That was a good day today," Hamilton told reporters. "Overall a good building block for tomorrow and the rest of the weekend.
He managed to clock up 35 largely untroubled laps during the afternoon with Rosberg running for one lap further.
"We got through our run plans in both sessions," said Hamilton.
Rosberg praised the new track surface and the remodelled final turn 15 which now has a slope toward the outside of the hairpin bend.
"The new track surface is really enjoyable to drive. Challenging, but with good grip," said Rosberg.
"Turn 15 is interesting, as you can now try several different lines if you're attacking the guy in front, so that will be good for overtaking." Ferrari were the next best in the classification, with last year's winner Sebastian Vettel third fastest in 1:35.605 followed by Kimi Raikkonen.
"It was a decent day, we were testing a couple of things," said Vettel. "Historically we seem to do well when it's warm and today was quite warm." Raikkonen was less pleased after he struggled with the balance of his car early in the session.
"It was not a very smooth day," said the Finn. "I'm surprised that the lap time was not too bad. There's work to be done." Late in the session birthday boy Max Verstappen, who turned 19 on Friday, gave himself something to celebrate by pushing up to fifth behind the Ferraris with a lap of 1:36.037.
But the other Red Bull of Daniel Ricciardo was relegated to eighth place as the Force India of Sergio Perez and the McLaren of Fernando Alonso went sixth and seventh fastest respectively.
Alonso was using an upgraded engine package from Honda which means he will start from the back of the grid in Sunday's race.
He will revert to his old engine for the race, saving the more powerful new unit for next week's 'home' grand prix for Honda in Japan.
Earlier Rosberg had been quickest in morning practice on soft tyres, 0.494 sec ahead of Hamilton whose best lap was set on the slower medium compound.
The morning was brought to a dramatic halt after just 11 minutes when Kevin Magnussen's Renault burst into flames in the pit lane.
Magnussen, who had returned with smoke coming from his engine cover after just one lap, was forced to leap to safety when fire broke out outside the Renault garage.
The session was delayed for 15 minutes and Renault engineers managed to get the Danish driver back out for the afternoon session after frantic repairs, and he came in 19th fastest.