Jorge Lorenzo of the Fiat Team Yamaha pipped Ducati's Casey Stoner on his last lap of Saturday morning practice at Laguna Seca.
Stoner's fastest lap was set on his thirteenth lap of the 23 he rode. He was in the pits when Lorenzo's time knocked him off the top. Lorenzo had led at three other times during the session, and Stoner topped twice.
Stoner had to pit during the session to rest, and the team spokesperson said he was really exhausted after the session, and is resting now until qualifying. A photographer who was shooting him could tell by his body language on the bike that he didn't feel well.
Lorenzo's team-mate and world championship leader, Valentino Rossi, was third, after leading three times.
Fourth and fifth were Toni Elias (San Carlos Honda Gresini), who led once early on, and Andrea Dovizioso (Repsol Honda), who later fell while running eighth. He was not hurt.
Saturday's leading times were the fastest of the weekend so far for four of the top five riders. Rossi's Friday time was faster than on Saturday.
American Nicky Hayden (Ducati Team) led once during the session, and later fell off his bike. He went back out and was ninth overall. He was not hurt and there was only minor damage to his motorcycle. On his cool-down lap he popped wheelies in Turn Three and photographers in that area said he really looked happy.
The other American, Colin Edwards (Monster Yamaha Tech 3), also fell off and pitted to nurse the fingers on his right hand. But he got back out and was seventh overall for the session.
Chris Vermeulen (Rizla Suzuki) crashed for the second day in a row. Friday he was all right. Saturday he walked away stiff and limping.
Other leaders during the session included Marco Melandri (Hayate Racing Team), Dani Pedrosa (Repsol Honda) and James Toseland (Monster Yamaha Tech 3).