Casey Stoner had his first outing aboard Ducati machinery since rejoining the Italian manufacturer in a private test at Sepang on Saturday.
The two-time MotoGP champion was revealed as a Ducati test rider and ambassador for the 2016 season in November, rekindling a partnership that yielded 23 race victories and the 2007 title.
It brought to an end a five-year stint with Honda, for which Stoner had tested only occasionally since ending his full-time career at the end of 2012.
The Australian was riding last year's Desmosedici GP15 on Saturday - emblazoned with his customary No. 27 - and he will get chance to rack up further mileage on the bike on Sunday.
Stoner's first laps for Ducati since 2010 followed a two-day shakedown of the Bologna marque's new bike in the hands of test rider Michele Pirro, who also returns to action on Sunday.
Official riders Andrea Dovizioso and Andrea Iannone will have their first taste of the GP16 when pre-season testing commences in earnest at Sepang on Monday.