Championship leader Jorge Lorenzo beat his teammate Valentino Rossi to the top spot in the first practice session for the Italian Grand Prix.
Rossi, who is chasing an eighth straight victory at Mugello, looked set to dominate the afternoon as he threw in an early 1m50.573s lap to put himself over a second clear of the field. But Ducati's Casey Stoner edged ever closer during his first run, getting within 0.001 second of Rossi's pace and then beating it by 0.048sec next time around.
Both were then usurped by Lorenzo's 1m50.442s lap as the session hit the halfway mark, before Rossi reasserted himself with a lap of 1m50.065s. Lorenzo was not finished yet, though, and on his last run he beat his illustrious Yamaha teammate by a relatively comfortable 0.195sec.
Casey held on to third, ahead of Honda's Dani Pedrosa and Tech 3 Yamaha's Colin Edwards.
Alex de Angelis started Gresini Honda's promised upsurge on home ground with a promising sixth place, although his teammate Toni Elias fell from an early top ten spot to 12th.
Loris Capirossi (Suzuki), Andrea Dovizioso (Honda) and Marco Melandri (Hayate Kawasaki) made it four home riders in the top ten, with Frenchman Randy de Puniet (LCR Honda) getting among them in eighth.
Again Stoner was by far the best of the Ducati riders. Despite Nicky Hayden's desire to improve on his team's home track, he was only 15th, behind Pramac rider Niccolo Canepa, who had a fall at the first corner.
Mika Kallio was slowest of all on the second Pramac bike, while the Hernando team is missing this race while Sete Gibernau recovers from his latest collarbone injury.
Pos Rider Bike Time Gap
1. Jorge Lorenzo Yamaha 1m49.870s
2. Valentino Rossi Yamaha 1m50.065s + 0.195s
3. Casey Stoner Ducati 1m50.144s + 0.274s
4. Dani Pedrosa Honda 1m50.808s + 0.938s
5. Colin Edwards Tech 3 Yamaha 1m50.891s + 1.021s
6. Alex de Angelis Gresini Honda 1m50.898s + 1.028s
7. Loris Capirossi Suzuki 1m51.007s + 1.137s
8. Randy de Puniet LCR Honda 1m51.030s + 1.160s
9. Andrea Dovizioso Honda 1m51.236s + 1.366s
10. Marco Melandri Hayate Kawasaki 1m51.359s + 1.489s
11. James Toseland Tech 3 Yamaha 1m51.401s + 1.531s
12. Toni Elias Gresini Honda 1m51.823s + 1.953s
13. Chris Vermeulen Suzuki 1m52.171s + 2.301s
14. Niccolo Canepa Pramac Ducati 1m52.319s + 2.449s
15. Nicky Hayden Ducati 1m52.403s + 2.533s
16. Yuki Takahashi Scot Honda 1m52.607s + 2.737s
17. Mika Kallio Pramac Ducati 1m52.619s + 2.749s