Andrea Dovizioso declared that Ducati has finally 'fixed' years of understeer problems, after making his debut on the all-new GP15 at the start of the second Sepang MotoGP test.

The slimmer, more compact machine is the first to be designed by Gigi Dall'Igna, who joined Ducati from Aprilia at the end of 2013.

While retaining a 90-degree V4 engine and desmodromic valve system, the bike has been heavily revised to try and cure long-standing understeer problems and claim Ducati's first win since 2010.

The date of the GP15's debut, just five weeks before the opening race, reflects the magnitude of the changes - Dall'Igna determined to gather as much data as possible before committing to a final design.

Development rider Michele Pirro was initially slated to shakedown the much-anticipated new bike. However a change of plan saw Dovizioso and new team-mate Andrea Iannone given one GP15 alongside the earlier GP14.3.

Dovizioso was tenth (+0.941s) quickest on the timesheets, setting his fastest time with the GP14.3 - but couldn't hide his delight at the handling of the new bike.

"I'm really happy because we fixed the problem about the turning," he smiled. "It was the key point in the last two years. Now with the new bike from the out-lap I felt much better.

"The first test here with Ducati two years ago I felt from the out-lap the limit of entry and turning. Today from the out-lap I felt the bike became normal!

"I was so happy. I went on the kerb in the first and second corners and I didn't want to! I was so happy to have that feeling. It was really big.

"I think it is the key point to start to work in a normal way. Already last year we improved the speed a lot and arrived close to the best but now we are in a normal situation, with a really good base.

"We can work on the set-up and my line on the track in the normal way. I can play with the bike, so I can try to pick up the bike more, try to be less aggressive on entry and this is 100 percent the way to ride in MotoGP.

"Today we weren't so fast because the bike was completely new and so we didn't do so many laps, and then it rained in the afternoon. But the key point was the turning.

"Now we have to work on the set-up because the bike is completely different and our balance is not ok, especially for braking. With the GP14 the set-up was perfect but this bike we have to understand. It is just the first day."

The Italian added: "I hope and believe we have a big margin. It is a really new bike. It is not quite starting from zero, but before we could just change some parts. Now everything is different."

Dovizioso's best lap on the GP15 was a 2m 1.692s, compared with a 2m 1.355s on the GP14.3.

"Today I started on the 14.3 and I made the lap time very easy because I know that bike very well. But I made a 2m 1.6 with the new bike and the feeling is not so good. So we have to work with the GP15 from now. We have only one GP15 each at the moment."

New team-mate Iannone was 15th fastest (+1.728s), having spent all of his time on the GP15.

"At the beginning I had a problem with the GP14.3 so I passed immediately to the GP15. The first feeling is very good because the bike has a good agility. It is really fast in the change of direction. I'm really happy about this.

"When you want to change direction, like the first and second corner, the bike is more fast and more easy...

"I didn't have so much problem with understeer before. I never try a Honda or Yamaha. Only Ducati. For me the 2014 Ducati improved a lot and this bike improves more in the agility.

"I'm really happy. For sure we are not at 100 percent competitiveness because it is new and I was not pushing. I was trying to understand the bike and some settings.

"The GP15 is a good evolution, but also a little bit revolution."

Testing continues on Tuesday and Wednesday, with a fourth day available for Michelin tyre testing.

One further official test, at Losail, will then be available before the new season starts at the same Losail circuit on March 29.