Nicky Hayden advanced from tenth to joint fifth during day two of the Jerez test, as the American concluded his second outing for Ducati one-second from Valentino Rossi and Dani Pedrosa, but just 0.022sec from third fastest Jorge Lorenzo.
The 2006 world champion lowered his best lap time by 1.6sec during his fourth day on Bridgestone tyres and was the fastest of the five Desmosedici riders present in Spain - factory team-mate Casey Stoner being unable to ride due to recent wrist surgery.
"We've made a big improvement today," said Nicky. "It was important to have back-to-back days with similar conditions because at Valencia we only had one dry day and we weren't able to check that the changes we made to the bike overnight had worked.
"Today my feeling with the bike was much better from the first run and it is important that we've taken over a second and a half off my best time from yesterday.
"We are still a second off the top guys and I know the last second is the most difficult to find but at the same time we're less than a tenth off third fastest and the team is working well, I feel more and more comfortable with the bike and tyres and I can head home with a clear mind.
"I was pleased that Casey wanted to be here at the test," said Hayden of Stoner's presence as a spectator. "It has been useful to speak with him and Filippo [Preziosi] and it shows how tight the team is and how well everybody wants to do next season! I just want to finish by saying 'Happy Thanksgiving' to everybody in America!"
Hayden's next on-track appointment will be the first test of 2009 at Sepang in Malaysia from February 5-7, when 2007 world champion Stoner aims to make his return.