Yamaha's Brivio: we were too cautious

Although Yamaha were tipped as favourites to dominate the opening race, it was Ducati's Casey Stoner who took victory, upstaging seven-time world champion Valentino Rossi to score his maiden win in MotoGP.

Stoner used the Ducati's impressive power advantage to beat Rossi with a 2.8 second advantage.

Brivio said he was impressed by the Italian bike's performance, but claimed Yamaha had been too cautious in the race.

"We were too cautious and ended up with a lot of fuel on board," Brivio was quoted as saying by Gazzetta dello Sport. "It's the Japanese mentality: they did thousands of calculation, but then took almost no risks at all.

"The Ducati was impressive. Taking for granted that everything is within the rules - because you can't think otherwise and in any case I believe the stewards did their checks - everyone in the paddock, not just us, is wondering how they managed to find that sort of performance.

"We must understand how they made their engine go so quick, and we must try to close the gap."

Yamaha's racing department boss Masao Furusawa admitted he was surprised by Ducati's impressive form.

"When I saw what was happening on the straight, my brain awoke abruptly," he said. "Ducati have a small factory, but they've worked very well. I haven't told our engineers to work faster, but I told them to re-analyse the data in depth.

"We have some evolutions which we'd like to take to Jerez, but I don't know whether we'll have time to use them in the race."