Melandri rode a heroic race to come tenth to third with a swollen ankle following his high-speed crash in qualifying.
"It was an amazing race, it's unbelievable. I needed an injection for the pain," Melandri said. "The last five or six laps I started to feel some pain and I couldn't downshift very well but I made it to the podium."
Rossi's Yamaha was the first bike to finish using Michelin tires and he again complained after the race about the new tire rule even though it has created a level playing field.
"Today was incredibly disappointing because with the tire situation like this, it was like our rivals were in a different race," Rossi said. "My team and I worked very hard, especially after yesterday's crash, and we did the maximum we could to have our bike in the best possible condition but without grip it was impossible to fight with the leaders."
Rossi now has 177 points with Stoner leading on 221 and Dani Pedrosa, who faded to fifth today, third on 155 points.
First of the American riders to finish was wild card Roger Lee Hayden who was tenth on a Kawasaki in his first-ever race on a MotoGP bike.
"I tried to run a consistent race and it's a shame Alex Barros
got me at the last corner, but the top ten is a good result and I've learned a lot," Hayden said.
Ahead of Hayden were his Kawasaki teammates Randy de Puniet (sixth) and Anthony West (seventh) who both raced impressively.
Texan Colin Edwards finished eleventh and Hopkins way back in 15th after his early crash while trying to pass Nicky Hayden.
Edwards said despite many set-up changes a lack of grip made him uncompetitive.
Hopkins said: "It definitely sucks and I'm really disappointed at my home race. I got a good start and went into the turn right up there. Somehow Nicky came wide and I went up the inside of him, but as I did that I guess he didn't see me and as he cut back in we came together. He hit my front brake lever and I went down."
After the race Ducati announced that Stoner had added a third year (2009) to his already confirmed contract until the end of 2008 and that for next season Marco Melandri would be his teammate.
This means the end of Loris Capirossi's career at Ducati and an announcement that he will join Suzuki is expected in the coming days. Capirossi's teammate at Suzuki will be Vermeulen who confirmed he had re-signed for 2008 after his second place at Laguna Seca.
