Having downplayed his chances heading into this weekend, Valentino Rossi made full use of an upgraded Yamaha engine to lead Friday free practice at Motegi in Japan.

It marked the first time that the nine time world champion had led a MotoGP track session since Friday practice for round four at Mugello, on June 4. Rossi broke his leg the next day and missed four races.

"I'm really happy about today, it is honestly a big surprise for me to be first!" said Rossi, who has been struggling with a shoulder injury, suffered back in April on a motocross bike, rather than his healing leg.

"I was expecting to suffer a lot here with my shoulder because there are so many hard braking areas but in fact they are all quite straight so I was happy to find I was okay. In fact I felt very good on the bike right from the start and we have done a great job here with the setting.

"I used the new engine and Yamaha have done an excellent job on it, it is especially better in fourth and fifth gears and everything is working very well. I know it's only Friday but it's a long time since I have been in front like this so I have to enjoy this sweet feeling!

"I know there's a chance of rain for the rest of the weekend, which is a pity, and if it is wet we will do our best. I am sorry for Dani; I saw the crash from far off and it's bad luck, I hope it is not too bad," he added, referring to the accident that left the title-contender Pedrosa with a broken collarbone.

"It's been a while since we finished a session in first!" confessed team manager Davide Brivio. "This was a really good practice for us because firstly it's nice to be in front but more importantly because Valentino was able to ride fast from the start. Our base setting worked very well here. We used the new upgraded engine for the first time and it is working well. We are in good shape and we hope to continue like this tomorrow."