It may not be much to shout about, given Valentino Rossi's illustrious achievements, but fifth place and 0.727sec from the front during first practice for the season-opening Qatar MotoGP is his best performance to date for Ducati.

The seven time MotoGP champion hadn't been higher than eighth, or closer than 0.767sec to the front, throughout the ten days of winter testing - and was only 13th fastest at the end of pre-season testing at the same Losail track on Monday.

But the Italian made clear progress on Thursday and has the potential to fight for a debut Desmosedici podium on Sunday if he can continue the momentum.

"We're all pretty satisfied with this first free practice because we worked well throughout the entire session, progressively improving with each outing," said Rossi, who won last year's Qatar race for Yamaha.

"We modified the setup a little compared to the test, and we immediately found it to be better, to the point that within just a few laps, I improved on my time from Monday.

"The last run was particularly positive and my final lap time, done with a hard tyre that had 19 laps on it, was my best, a bit more than a tenth off of second place. We know that if we want to have a good race on Sunday, we have to cut another five tenths, and we'll try to do that tomorrow.

"Anyway, although we still have to improve some more things on the bike, now I don't have to push so hard and it is turning better. The shoulder is holding up well. It was only at the end that it started to lose a little strength, and tomorrow we'll see how it reacts with two practice sessions. In any case, we're happy today."

Team-mate Nicky Hayden started quite well, immediately matching his best time from the test, but couldn't improve further and was left in eleventh place.

"The session started out pretty well. I immediately went out with a hard rear tyre and a soft front, which isn't my favourite setup, and I was able to match my lap time from the test by the fourth lap," said Hayden. "I felt quite good, but from there, I never really was able to improve much. Obviously everybody else got quicker, so I'm not thrilled with that time."

The top Ducati on Thursday was Aspar's Hector Barbera, who made the most of a tow from Hayden to claim a shock third place.