New world champion Jorge Lorenzo stamped his authority on the first day of post-season MotoGP testing, taking the new #1 plate on his factory Yamaha to the top of the timesheets by 0.763sec at Valencia on Tuesday.
Rain in the morning saw the day's session delayed until the track had dried with all riders waiting until the afternoon before venturing out onto the circuit.
Once out on track, Lorenzo continued the form that took him to victory in Sunday's season finale, taking just five warm up laps to go straight to the top of the timesheets where he remained unbeaten for the entire session.
The Mallorcan split his riding time between the 2011 prototype M1 and an updated version of his 2010 machine.
"Today we tried the new chassis on the 2011 M1 which felt good, although it is still to early to say too much about it," said Lorenzo.
"We also tried the new Ohlins suspension which felt better to me on the track. The new engine seems to have less wheelie but we will see more tomorrow in the next session."
"2011 has started I would say!" added team manager Wilco Zeelenberg. "We finished the session on top so I think everything went quite well. Our lap times were good and we improved on our qualification time from Sunday's race. We managed to test everything we wanted to today so tomorrow we will continue with more and see how far Jorge can go."
New Honda rider Casey Stoner got closest to Lorenzo on Tuesday, while new team-mate Ben Spies - taking Valentino Rossi's place - was third fastest out of the 17 riders.
Rossi was tenth on his Ducati debut.
Although still riding with Fiat livery, Yamaha is presently without a title sponsor for next season.