Red Bull's Mark Webber continued to set the pace in practice for the Malaysian Grand Prix on Friday, the Australian setting the fastest time in both sessions around a sweltering Sepang circuit.
Webber endured a disappointing season-opening race in Melbourne, finishing well behind team mate Sebastian Vettel down in fifth place, but made good on his promise to arrive in Malaysia with a far more competitive car.
After topping the timesheets by 1.665 seconds in the morning, Webber made light of an on-track temperature of 49 degrees Celsius to record a fastest lap of one minute, 36.876 seconds in the afternoon.
However, Red Bull's closest title rivals McLaren will take heart from the fact both their cars finished within 0.134 seconds of Webber in the faster second practice session.
Jenson Button, winner of this race on his way to the world title in 2009, was just five thousandths of a second behind the Australian and may have gone quicker had he not wobbled slightly on the final turn before the home straight.
Fellow Briton Lewis Hamilton, who was second fastest in the morning, was a further 0.129 seconds back in third place, just ahead of Webber's team mate and reigning world champion Sebastian Vettel.
The top four appeared far more comfortable with the testing conditions around the demanding Sepang circuit as the best of the rest, Michael Schumacher, laboured almost a second behind Vettel down in fifth place.
Ferrari also had a poor race in Melbourne after impressing in pre-season testing and the Italian team's lack of pace looks set to hamper their chances this weekend as Felipe Massa and Fernando Alonso were never a threat to the leaders.
Brazil's Massa was sixth in both sessions while his Spanish team mate Alonso fared even worse, creeping into the top 10 each time with laps hardly likely to cause the front-runners to lose any sleep.
The earlier session was marked by a couple of high-speed accidents involving Renault's Vitaly Petrov and Virgin rookie Jerome d'Ambrosio but the later session was less eventful with just one mishap of note.
Williams' Pastor Maldanado had looked impressive before running into the barriers at turn 15, where it appeared he was going too fast entering the pitlane.
The Venezuelan rookie was fifth fastest in the morning but failed to improve on his 11th place time in the afternoon once he hit the barriers with 40 minutes of the session remaining.
HRT, equipped with a new front wing after failing to qualify for the season opener in Melbourne, and Team Lotus were both well off the pace at the back of the field and could struggle to make the starting grid under the 107 percent rule in qualifying.
