Casey Stoner won his second straight Australian Moto GP at Phillip Island on Sunday, leading from pole position for the entire race to notch a 6.5-second victory over Valentino Rossi. Ducati's Stoner, the 2007 world champion, finished the 27-lap race in a time of 40 minutes, 56.643 seconds, then grabbed an Australian flag for a victory lap around the circuit. Yamaha's Rossi, who wrapped up the 2008 world championship last week with a win in Japan, secured his 12th straight podium finish in Australia after moving up from 12th on the grid after a crash in qualifying Saturday. Honda's American Nicky Hayden finished third. It was Stoner's fifth win of the season. Hayden stayed with Stoner for much of the first half of the race before the Australian gradually widened the gap. With 10 laps remaining Stoner had taken a comfortable 4.5-second edge over the American, who will join him next season at Ducati. But the highlight was Rossi's masterful ride from the fourth row of the grid. By the end of the opening lap he was in eighth place, improving to fifth three laps later. The Italian then challenged fellow Yamaha rider James Toseland for third, slipping past the Englishman on the seventh lap. Spaniard Dani Pedrosa of Honda, third in the world championship behind Rossi and Stoner, failed to complete a lap, spearing off the track at the first turn. Earlier, Metis Gilera rider Marco Simoncelli of Italy extended his lead in the 250cc championship and Mike di Meglio of France wrapped up the 125cc world title with wins in their races after starting from pole position. Simoncelli finished his 25-lap race in a time of 39:02.553. Alvaro Bautista (39:02.776) on an Aprilia and Mika Kallio on a KTM, the two riders who trail him in the world championship standings, were second and third respectively. Simoncelli will take a 37-point lead over Bautista into the final two races of the season in Malaysia and Valencia, Spain. Di Meglio's Ajo Motorsport Derbi recovered from a sluggish start that left him seventh on the opening lap to take the lead on the second of 23 laps in the 125cc race. He streaked away from the field to finish in 37:55.589. German Stefan Bradl of Kiefer Aprilia, who won last week in Japan, was second, 10 seconds behind, followed by Hungarian Gabor Talmacsi of Bancaja Aspar Aprilia.