Valentino Rossi is preparing for another showdown with title rival Casey Stoner, following their epic dispute last time out at Laguna Seca, after finishing just 0.179secs behind the Ducati rider in Friday free practice at Brno.
With the newly surfaced track adding an unknown factor to the day's proceedings, the Italian was relieved to find his Bridgestone-shod Fiat Yamaha working well from the start - and he edged out Stoner by 0.129secs to be fastest of all in the morning session.
"I've had a good holiday but it's fun to be back on the bike again!" began Rossi. "Today has started very well and I am very happy with my bike and with our tyres, it seems the Bridgestones are working very well here so far.
"The new asphalt is good, much better than last year and the grip improved throughout the day so I think that they have done a good job."
With rain a possibility on Saturday, Rossi and Yamaha were keen to get through as much of their tyre programme as possible and Rossi tried several different combinations during the afternoon session, which he finished in second position, 0.179secs behind the Australian.
"Casey is strong again here so it looks like being a hard race, but we have made a good start," stated Rossi, who holds a 25 point lead over Stoner after his US GP victory. "Tomorrow it seems it could rain, which is a pity, but we have found a good setting today so hopefully, even if it is wet, then we will be in good shape on Sunday."
It is unclear exactly what new parts Rossi will try during the grand prix weekend and which will be tested on Monday and Tuesday, but Rossi played down the significance of the developments, which are believed to include revised electronics.
"We have some small engine modifications here to try but mostly we will wait until Monday to try the new parts, when we will have an important test," he said.
A 0.59secs gap separated Rossi from third fastest Loris Capirossi, of Rizla Suzuki.
Rossi's rookie team-mate Jorge Lorenzo, like all the Michelin riders, had a more difficult day and could only managed eleventh on the timesheets.