Having tried Ducati's latest electronic updates during the Portuguese MotoGP weekend, Valentino Rossi and team-mate Nicky Hayden set about the more complex task of evaluating a new chassis and engine - as well as the 2012 Bridgestone tyres - during Monday's official Estoril test.

It was a big day for the under-pressure Italian team, which took a podium with Hayden in the wet of round two at Jerez, but is yet to fight for leading positions in the dry.

Fortunately for Ducati, Rossi - who matched his best finish of the season with fifth place on Sunday - gave all the developments his seal of approval.

In particular, Rossi singled out the chassis changes as finally making a predictable impact on the front-end behaviour of the GP11.

"It was a positive test because the new updates were immediately better," said Rossi. "The bike was more sensitive to changes made to the front, which makes it easier to work on a set-up that works better for me.

"I realised that as soon as I got on the bike and then, over the course of the following hours, we constantly progressed."

Rossi is likely to use the new chassis from the next round at Le Mans, on May 13-15, but the limit of six engines for a season means he will have to wait until the mileage on his existing powerplants has been exhausted before running the revised engine.

"We also had an engine with a slightly smoother power delivery that I liked a lot. We'll start using it when the rotation plan allows it," confirmed Rossi, who also liked the 2012 tyres: "They seemed very good".

The seven time MotoGP champion was fifth fastest after his 82 test laps, but still 1.171sec behind Honda's Marco Simoncelli.

The Italian megastar confessed that the size of the gap was troubling, but insisted he and Ducati are now getting into their stride.

"Of course the other riders also made great progress, and the less positive about today is the gap to the front on my best lap," he said. "Anyway, everything that the Ducati technicians brought worked, and that means that we're on the right path.

"We have to continue working, but today's test gives us confidence."

Hayden was less than a tenth slower than Rossi, in ninth.

"We improved, because I consistently went a lot faster than in qualifying, but it looked like everybody else improved too," said the American. "I did my best time on the 2012 tyres, so Bridgestone made a nice step there."

The 2006 world champion also felt the chassis and engine updates were in the right direction, but didn't seem to feel they had made a huge difference.

"I got on the updated chassis after lunch, and it had a better feel over some of the bumps, and still good stability under braking. The updated engine made the bike a little smoother, and I liked it overall," he said.