Summary Marquez set the best wet time ahead of Pedrosa and Italy's Valentino Rossi on a Yamaha.
BRNO (AFP) - Championship leader Marc Marquez topped the Czech Republic MotoGP free practice on Friday ahead of Sunday s race, with the afternoon session disrupted by heavy rain that affected times.
The Spanish Honda rider and reigning world champion took 1min 56.803sec to cover the 5.4-kilometre (3.36-mile) circuit in dry conditions on Friday morning.
Fellow Spaniard Jorge Lorenzo on a Yamaha came second 0.037sec behind his compatriot and 0.015sec ahead of Marquez s Honda teammate Dani Pedrosa.
Marquez, who tested a new bike for the 2015 season at Brno together with Pedrosa in July, said the conditions were different this time.
"From the first exit I saw that the grip was different," he said.
"I started to change something on the bike because I didn t feel good but we did a really good job and in the end I was happy with the setup."
Lorenzo was equally happy with his performance on the dry track.
"In the morning we were really satisfied because suddenly we were very competitive," he said.
Italian Ducati rider Andrea Iannone dominated the afternoon session with a time five seconds slower than his morning performance, being one of only two riders who had their times measured before the downpour started.
Marquez set the best wet time ahead of Pedrosa and Italy s Valentino Rossi on a Yamaha.
"The biggest problem was two corners in the downhill, turn 10 and 11 were completely dry in the end so one part of the circuit was completely wet and the other part completely dry," said Marquez.
"For that reason it was difficult to manage the tyres because when you push there you destroy it."
Forecasters predict more rain for Saturday s practice and qualifying sessions.
"This afternoon it was wet and we were not competitive compared to the Hondas, especially in the first laps," said Lorenzo.
"We don t have so much grip, we need to find some. If it rains, we re going to struggle."
At Brno, the 21-year-old Marquez is eyeing an 11th straight win in as many races this season, which would be a new record.
Italian legend Giacomo Agostini won the opening 10 races of the premier class season in 1968, 1969 and 1970, and Marquez equalled that feat at Indianapolis last Sunday.
At Indy, Marquez also became the first rider since Australian Mick Doohan in 1997 to win 10 races in a row.
However, no one has ever won the first 11 races of a season -- in part because Agostini s perfect season in 1968 comprised only 10 events.
After 10 of 18 MotoGP races this year, Marquez leads the championship standings with a perfect 250 points, 89 ahead of fellow Catalan Pedrosa and 93 ahead of Rossi.
