Jorge Lorenzo set the quickest time of Monday's MotoGP test at Brno as Yamaha continued its domination of the class.
The 22-year-old Spaniard's best time of the day was half a second quicker than team-mate Valentino Rossi, who still finished the test second fastest ahead of the Honda of Dani Pedrosa and the Suzuki of Loris Capirossi.
Lorenzo bounced back from his disappointment on Sunday, when he crashed out of the lead of the race, and set a best lap just 0.016s slower than Rossi's pole time on Saturday.
"Today was a profitable day and we worked on a lot of different things, especially electronics," said Lorenzo. "I felt comfortable and I could ride in the 56.1s, which was good after yesterday.
"I hope that everything we've done today will help us at Indianapolis. I'm not thinking about the championship now because it's very difficult unless something strange happens, but I want to try to be back at the front and I'm looking forward to the next race."
The afternoon's running was cut short due to heavy rain, but championship leader Rossi was still happy with his day's work after testing several 2010 parts.
"It's always hard to go back to work after a great win like yesterday but it was an important chance to try some things for the future," he said. "Before lunch we did a run with the new chassis, it has some good points and some bad ones and we were able to collect some data.
"Unfortunately it rained in the lunch break and so we couldn't ride for a lot of the afternoon because of the wet rack, but it dried enough for us to do some more work at the end. This time we could really concentrate on doing a proper job testing the chassis and the new engine specification."
Andrea Dovizioso finished the test fifth fastest on the second works Honda, with Toni Elias the first of the customer bikes in sixth on his Gresini Honda.
Mika Kallio finished the day 10th on his works Ducati, just one tenth of a second and two places behind team-mate Nicky Hayden. Mattia Pasini, who took Kallio's place at the Pramac Ducati team for the test, ended the day 13th fastest.
Pos Rider Bike Time
1. Jorge Lorenzo Yamaha 1m56.171s
2. Valentino Rossi Yamaha 1m56.622s
3. Dani Pedrosa Honda 1m56.747s
4. Loris Capirossi Suzuki 1m57.543s
5. Andrea Dovizioso Honda 1m57.764s
6. Toni Elias Gresini Honda 1m57.841s
7. Chris Vermeulen Suzuki 1m57.891s
8. Nicky Hayden Ducati 1m57.928s
9. Marco Melandri Hayate Kawasaki 1m58.045s
10. Mika Kallio Ducati 1m58.051s
11. Niccolo Canepa Pramac Ducati 1m58.120s
12. Gabor Talmacsi Scot Honda 1m59.008s
13. Mattia Pasini Pramac Ducati 1m59.614s