...championship leader Casey Stoner of Australia in a flying last practice lap.
Stoner dominated morning practice but it was the 25-year-old Yamaha rider who ended up on top, pushing his yellow-painted Yamaha to the limit in the final lap of the second practice round with a time of one minute 58.362 seconds.
Stoner, 21, who has won six out of 11 races this year on his powerful Ducati, settled for the second fastest time of 1:58.568, 0.3 seconds ahead of American John Hopkins on a Suzuki. The Australian leads the championship with 221 points.
Seven-times world champion Valentino Rossi, who trails Stoner by 44 points in the overall standings, could manage only the sixth fastest time on his new Yamaha.
The undulating 5.4-km Masaryk Ring has been kind to the flamboyant Italian over the years. Rossi has snatched three wins and three second place finishes out of seven starts in the MotoGP class on the track, as well as wins in the 125cc and 250cc classes.
Spaniard Dani Pedrosa, behind Rossi with 155 points this season, dropped one place in the afternoon session, clocking only the seventh fastest lap of 1:59.266 on a Honda.
Defending champion Nicky Hayden, who interrupted Rossi's five-year podium reign in Brno last year, struggled again on Friday, finishing 0.200 of a second behind Pedrosa.
[Reuters/Finance.cz]