Nicky Hayden made his much anticipated Ducati debut during the opening day of the post-race Valencia test, on Monday.

The American, whose entire grand prix career has been spent at Repsol Honda, now needs to adapt to a new bike, team and tyres for the 2009 season - and previously admitted the 800cc Ducati's reputation for thwarting all but Casey Stoner made him a little apprehensive.

At 11am this morning the Ducati pit garage opened its doors to reveal a special stars and stripes coloured Desmosedici for the 2006 world champion. Hayden, who finished sixth in the 2008 standings with two podiums, initially rode this year's GP8 before turning his attention to the new GP9.

Hayden improved his pace throughout the day, stopping the clock with a best lap of 1min 33.960sec. That placed the American twelfth out of the 18 riders present, 1.496sec from Stoner but within 0.6sec of his best lap on a Michelin-shod RC212V, set on his way to fifth in Sunday's grand prix.

Marco Melandri, whom Hayden has replaced, set a fastest time of 1min 34.117sec (using the GP8) in Sunday's race.

Like most riders still under contract for another manufacturer, Hayden has to pick his words carefully and is unable to make direct comparisons between the Ducati and Honda grand prix machines at this stage.

However, Hayden did say that it had been an 'intense' first day, and that while he has 'a lot of work to do' he 'really enjoyed himself'.

"It has been a very intense day and full of many things to test and to understand, but it was exactly as I expected it to be," said Nicky. "I did just one run with the GP8 and then I switched completely to the GP9.

"Obviously there is a lot of work to do but I am happy, it was a good day that has allowed me to understand that the bike has good potential and, more than anything, I can say that I really enjoyed myself.

"This first day has given me an appreciation of the bike and the team. One of the things that really impressed me the most was the acceleration. I found myself pretty comfortable on the bike, and I really didn't make a lot of changes to levers and handlebars.

"We have not even changed a lot the settings, we have just made some small changes, some mapping settings, a couple of tyres, in order to try and understand the direction of the bike and to feel comfortable on it."

With one day of running under his belt, the amount of progress Hayden makes on the second and final day of the test could well provide a good indication of just how quickly he will adapt to the Desmosedici.