Jorge Lorenzo sealed his second world MotoGP crown after his challenger crashed out, while Casey Stoner claimed his sixth straight Australian Grand Prix at Phillip Island yesterday. Spain's Lorenzo took the title despite finishing second behind the rampant Stoner, who thrilled his 53,000 home fans by storming to a nine-second victory in his final ride at his favourite track before retirement. Lorenzo's task was made considerably easier when Stoner's Repsol Honda teammate, Dani Pedrosa, crashed out on the second lap. Lorenzo had led Pedrosa by 23 points going into the penultimate Phillip Island round. He only needed to finish three points higher than his compatriot to secure the championship before the final race in Valencia on November 11. Pedrosa was leading when he high-sided and lost control of his Honda on the right-handed turn four and his race was over in a matter of minutes after the start. The unstoppable Stoner took over to draw away from the field for a convincing win, his 38th in 114 MotoGP starts. "I was quite comfortable to be in second place because Casey was in another world, so I thought I had a great chance to become world champion today," Lorenzo said. Lorenzo heads to Valencia with an insurmountable 43-point lead over Pedrosa.