Ducati MotoGP project director Livio Suppo believes Casey Stoner's sixth place in Sunday's Portuguese Grand Prix was 'one of his best races' - as the MotoGP world champion battled set-up problems and loose camera equipment.

The set-up problems may have been a frustration - and had left the Australian just ninth on the grid - but the loose camera equipment, which flapped dangerously between his handlebars and front fairing, was much harder to accept.

"It was incredible what happened today, we had a problem which was no fault of the bike from the beginning of the race," said Stoner. "I didn't understand what was going on and wasn't sure if an important part of the bike was involved. It was a major distraction.

"Sometimes the piece would lock the steering and sometimes it locked the clutch lever. It was a very difficult situation but eventually I worked out a way to ride around it. Every time I came down the straight I pushed it back into place but the turbulence from the wind would blow it back out again so it was very frustrating.

"I think a better result for sure was possible without this but we have to take this as a positive thing and not reflect on the negatives. It wasn't a good weekend for us but the problem in the race was not a general fault with the bike, just one of those things that happens from time to time. We need to continue working hard in China, a track that should be a little better for us, and hope for a bit more luck," he concluded.

Despite the problems, Stoner - who had slipped back to eleventh during the middle stages - produced an impressive second half charge to climb back up the order. The 22-year-old overtook Chris Vermeulen, Randy de Puniet and James Toseland, while Andrea Dovizioso and Nicky Hayden crashed out ahead of him.

"I actually think this was one of Casey's best races," said Suppo. "He had the composure to take control of the situation when a quite unusual problem came out. He was able to hold his nerve and he produced an outstanding ride, with the fourth fastest time of the race and important points for the championship. It's been a strange weekend but Casey is still in there, his potential remains intact and we're happy about that."

Stoner remains fourth in the world championship standings, 21 points behind joint leaders Jorge Lorenzo and Dani Pedrosa, but team-mate Marco Melandri is just 13th in the championship table after his worst race result of a nightmare season so far.

"The result in the race is a direct reflection of a difficult weekend, during which we've been unable to find a satisfactory set-up for the bike," said Marco, who finished 13th. "All I can do is wait and hope that this proves to be the second of the two worst races for us this season and that things start to be more favourable from China onwards."

Stoner and his powerful Ducati won last year's Chinese Grand Prix, which features the longest straight on the MotoGP calendar.