Randy de Puniet was seventh for Honda LCR, with Bridgestone-shod Rossi eighth fastest on combined times - making him the slowest Yamaha and one of only three riders to lap slower in the second session.
Rossi's collision with Pedrosa came with 20 minutes of the second hour left to run, as the Italian exited a fast right hander. Rossi didn't seem to visibly shut off, but the speed difference between the pair was considerable and the young Spaniard was left raising his hands in disbelief after hitting Rossi's rear wheel, being thrown from his RCV and then rolling violently to a halt in the gravel.
Fortunately, Pedrosa didn't appear to re-injure his recently fractured hand, but the 2007
MotoGP World Championship runner-up still finished the first day of 2008 just tenth fastest, ahead of only one satellite RCV rider (Shinya Nakano) and having failed to beat his own FP1 time.
As revealed yesterday, the Repsol Honda team-mates swapped between the '07 and '08 version of the RC212V - but with little apparent success. Pedrosa's team-mate
Nicky Hayden was the slowest Honda rider in 13th and ran off track late in the hour.
Also having a difficult night were Suzuki and Kawasaki, with
Chris Vermeulen the lead GSV-R rider in ninth, while former team-mate
John Hopkins was the top ZX-RR competitor back in 14th. New team-mate
Anthony West fell at the end of the second hour on his way to 17th, with
Loris Capirossi 11th on the second Rizla machine.
Stoner's team-mate
Marco Melandri was once again at the lower end of the timesheets, the Italian finishing the opening day just 15th fastest - one place ahead of former Honda team-mate
Toni Elias, now riding a satellite Alice-backed Desmosedici.
Friday practice:
1. Stoner
2. Lorenzo
3. Toseland
4. Edwards
5. Dovizioso
6. de Angelis
7. de Puniet
8. Rossi
9. Vermeulen
10. Pedrosa
11. Capirossi
12. Nakano
13. Hayden
14. Hopkins
15. Melandri
16. Elias
17. West
18. Guintoli