Spaniard Jorge Lorenzo shook off any rust from missing the final three races of 2011 due to injury by posting the fastest time on the first day of pre-season MotoGP test runs, in Malaysia, yesterday.

Yamaha dominated to open the three days of tests at Sepang, with three of its riders among the top four, while 2011 champion Casey Stoner, of Australia, was sidelined by a pulled back muscle as teams unveiled their new 1,000cc bikes.

The testing session marked an emotional return for riders to the Sepang circuit for the first time since Honda rider Marco Simoncelli died in a shocking crash in October’s Malaysian MotoGP.

On Monday, Honda team officials laid a flower wreath at turn 11, where the 24-year-old Simoncelli was killed, and observed a moment of silence.

Lorenzo’s 2011 season ended prematurely when he crashed during warm-ups for the Australian Grand Prix.

But he set the fastest pace yesterday on his Yamaha in hot and humid conditions with 2.0 min 01.657 seconds while his countryman Dani Pedrosa, with rivals Honda, was next with a time of 2:02.003.

Yamaha’s Carl Crutchlow, of Britain, posted a third-best 2:02.221 while his team-mate Ben Spies, of the United States, followed up in 2:02.234.

MotoGP has moved to 1,000cc bikes this year in place of the earlier 800cc engines.

Meanwhile, multiple world champ Valentino Rossi, who struggled through a difficult 2011 season, posted a fifth-fastest lap time of 2:02.392 on his Ducati Desmosedici GP12.

Testing ends tomorrow and is followed by another three-day session at Sepang beginning February 28. The MotoGP 2012 season will officially start in Qatar on April 8.