(CNN) -- Jorge Lorenzo edged out Yamaha team-mate Valentino Rossi to set the fastest time in practice ahead of the Czech MotoGP in Brno this weekend.
Lorenzo looks the rider to beat in the Czech MotoGP after setting the fastest time in practice.
The young Spaniard posted a best time of one minute 56.59 seconds, 0.39 seconds quicker than his Italian rival.
Dani Pedrosa was third quickest on his Repsol Honda, while the in-form Colin Edwards (Monster Yamaha Tech 3), Pedrosa's Italian team-mate Andrea Dovizioso and Spanish rider Toni Elias completed the top six.
Lorenzo was delighted to get off to a flying start on a track where he has enjoyed success before. "It's a great thing to start the weekend in such a strong way and I've had a good sensation and feeling with my bike from the first moment today," Lorenzo said on www.motogp.com.
"This isn't usually the case so I'm really happy. I like this track a lot. I've had three wins here in the past and I always feel confident riding here."
Rossi leads the championship standings by 25 points from Lorenzo after coming fifth last time out at the British Grand Prix, where Lorenzo failed to finish.
After Friday's practice session the Italian said: "Jorge and I were very fast from the start of this session, which shows how good our bike is and what a great job Yamaha has done back in Japan.
"We've worked well and we've already shown some interesting lap times. The setting isn't perfect yet though so we need to work more, especially on the tires because this track is very hard on both the front and rear.
"I hope the surface improves as more rubber is laid down because at the moment the grip isn't great."
Rossi also gave his support to Australian rider Casey Stoner, who has been given a three-race break to recover from the fatigue-inducing illness he is suffering.
He added: "I'm really sorry that Casey Stoner isn't here, I would always rather have my rivals to race against and I would like to wish him all the best. I hope he's back soon."