Stoner claims easy win in Czech Grand Prix

The victory at the undulating 5.4km Masaryk Ring was the Australian's seventh of 12 races this season.

"Everything worked perfectly today, the bike, the tyres. I was fast at the beginning... so I could relax slightly towards the end," 21-year-old Stoner said.

American John Hopkins, who started from the front row, led his Suzuki unchallenged to claim second place, trailing Stoner by 7.903 seconds.

"Casey's pace was unreal, he didn't make a mistake the whole race so it was tough to catch him," Hopkins said.

Hopkins' compatriot and world champion Nicky Hayden shrugged off some disappointing practice sessions to clinch third place, a further 5.197 seconds behind.

"Yesterday afternoon we made quite a big change on the front forks, and I liked it a lot and was able to dig down to (one minute) 58s (seconds laps)," Hayden said.

"Today, I kept my rhythm."

Hayden, who interrupted Valentino Rossi's five-year reign in the top class last year, has been struggling this season with only three podium finishes.

With six races to go, Stoner leads the championship with 246 points. He has extended the gap to 60 points over seven-times world champion Rossi, who finished a disappointing seventh on a Yamaha at his favourite track, 22.485 seconds behind the winner.

The flamboyant Italian had snatched three wins and three second-place finishes out of previous seven starts in the MotoGP class on the Brno track, as well as wins in the 125cc and 250cc classes.

Hayden's team-mate Spaniard Dani Pedrosa, who crossed the line fourth on a Honda, is the third overall with 168 points, closing on Rossi.

The next race is at San Marino's Misano circuit on Sept. 2.