Yamaha's reigning double MotoGP champion Jorge Lorenzo halted Dani Pedrosa's perfect sweep of 2013 Sepang testing by moving to the head of the timesheets on day two of the second Malaysian visit.
Pedrosa had been fastest for the previous five days of official testing, stretching back to the final day of the post-2012 test at Valencia.
The last time Lorenzo had finished on top of the MotoGP timesheets was at Sepang, in October, after taking pole position for the grand prix.
Lorenzo's return came after delivering his best lap of 2013 testing so far, a 2m 0.282s, on the 32nd of 58 Wednesday laps.
That was 1.5s faster than his Tuesday time and put him out of Pedrosa's reach by 0.369s, although Lorenzo was still a fraction shy of Pedrosa's 2m 0.1s best lap at the first test.
“I am happy. The lap times are good and that is always the best indicator of your performance,” said Lorenzo. “Sometimes you can feel faster, but the lap time doesn't change.
“The track was better today and everybody improved, so I would say 1-1.2s came from the track, then we kept playing with the setting of the suspension and electronics to find the rest.
“We improved the acceleration a little bit. Small details and also I think my riding is a few tenths better... We still need to improve acceleration.
“But I'm very satisfied with the pace, because I did a lot of my laps in 2m 0s. That is very positive.”
No less than 18 of Lorenzo's Wednesday laps were under 2m 1s - the Spaniard's own official pole record is a 2m 0.334s - compared with four laps for next best Pedrosa.
Lorenzo added that it could be possible for him to drop under the two-minute mark, for the first time ever, early on Thursday's final day. However it is not a priority.
“It depends on a perfect lap and the condition of the track. Probably at 10am tomorrow morning a 1m 59 will be possible, but the most important thing for me is to do a long run in 2m 0s if possible,” he said.
Team-mate Valentino Rossi was fifth fastest, 0.783s behind Lorenzo.
Pedrosa set a 2m 0.1s lap at the first Sepang test.