The Dunedin-based rider leads the competition standings with three wins from four races.
She is well placed going into the third round at Loket, in the Czech Republic.
The 23-year-old won both races in Portugal by a comfortable margin and will be the favourite in Loket.
But Duncan has learnt not to take anything for granted. She has been at the top of the standings before only for her campaign to be derailed by bad luck.
But she told the Otago Daily Times earlier this month she has put in a tremendous training block and is riding as well as she ever has.
She switched teams to Kawasaki this season and is really starting to get the best out of her new bike.
Duncan is determined to shed the unlucky tag and claim the title which has eluded her since her impressive rookie campaign went off course when she collided with a stray photographer three years ago.
Duncan has good memories from her previous trip to the Czech Republic, though.
She won at Loket in 2017 and will draw confidence from that.
