Casey Stoner made light of his recent illness to set the pace in the opening free practice session at the Sachsenring.

The Australian, who is suffering from anaemia, handled the damp track well to post a fastest time of one minute 22.779seconds.

The Ducati Marlboro rider's time was never threatened.

Stoner, who lies third in the overall standings, 16 points behind leader Valentino Rossi, was a comfortable 0.255s quicker than Spaniard Dani Pedrosa on the Repsol Honda, with Fiat Yamaha's Rossi third fastest.

Randy De Puniet (LCR Honda MotoGP), Alex De Angelis (San Carlo Honda Gresini) and Colin Edwards (Monster Yamaha Tech 3) completed the top six.

Rossi's team-mate and closest title challenger, Jorge Lorenzo, who is nine points off the lead, was perhaps still feeling the effects of his qualifying crash in the last round at Laguna Seca and could only manage 11th.

Briton James Toseland had to be content with 14th fastest, over one-and-a-half seconds slower than Stoner.

Lorenzo admitted afterwards he was not fully fit after his crash in America.

"I am not at 100% and in fact my injuries don't feel as good as I had hoped on the bike, which is disappointing," Lorenzo said on autosport.com.

"I have decided for the first time to use the leathers with the airbag and I want to say that I feel much more safe.

"This isn't the best track for me, the slow corners don't really suit my style and when I am not at full fitness it makes it more difficult, but today was okay considering the conditions."