Spaniard Dani Pedrosa dominated all free practices ahead of Sunday\'s Czech Republic MotoGP after coming on top in the third and last practice on Saturday. The Honda rider set the fastest time of the day at 1min 56.209 seconds ahead of US rider Ben Spiess on a Yamaha, trailing Pedrosa by 0.743 seconds. World championship leader Jorge Lorenzo came third, with a gap of 0.806 seconds on Pedrosa. The Spanish Yamaha rider, who leads Pedrosa by 18 points in the world championships, has thus come under more pressure after Pedrosa had narrowed the gap by winning in Indianapolis last weekend. Casey Stoner, third in the world championships and the winner of last year\'s Brno Grand Prix, retired from the race on Thursday to undergo surgery on his broken ankle in Australia.