James McDonald doesn't expect Hartnell to topple hot favourite Winx in the Chipping Norton Stakes but he is hoping the Group One winner can make a Sydney autumn carnival impact.

As Godolphin's No.1 stable jockey, McDonald chose to ride the BMW winner in preference to stablemates Magic Hurricane and Hauraki who will both have a fitness edge at Randwick on Saturday.

McDonald has shown loyalty to the five-year-old who he partnered in all four starts during the spring, including a fifth to Winx in the Cox Plate.

Hartnell hasn't won since his BMW triumph in March last year and has been placed once in four first-up runs.

Despite that statistic, he is the horse rated the best chance to defeat Winx who dominates betting as the $1.40 favourite.

At $8, Hartnell is the only other one of the 12 Chipping Norton runners at single-figure odds.

Caulfield Cup winner Mongolian Khan, racing for the first time since a bout of colic cruelled his Melbourne Cup aspirations, shares the third line of betting with Dibayani at $12.