The ranking puts Moscow-born Katia, and Harley, a young indigenous man from western Sydney, in strong medal contention heading into what is guaranteed to be a thrilling free skate to determine the 2017 Junior World Champions late Friday evening.
Their score of 59.82 in their short program is just two points behind the leaders, Russians Aleksandra Boikova and Dimitrii Koslovskii.
The Australian pair were awarded small bronze medals for their short program at a press conference for the top three pairs after the event.
“We have come a long way in a short time,” Windsor said when asked about how the relationship works between the two. “You approach it as a business partnership and keep it very professional, as it is just like a full time job, and so you need to respect one another.”
Windsor’s parents were among bleary-eyed supporters celebrating in Sydney after getting up in the middle of the night to watch the couple nail a triple twist lift, perfect side by side double axels and a throw triple flip - a difficult element that only a handful of skaters in the world can do - to notch a new personal best.
China's Yumeng Gao and Zhong Xie are in second.
In the men's short program earlier in the day South Australian dynamo James Min finished 29th with a PB of 53.72.
The competition continues today with Sydney couple Matilda Friend and William Badaoui in the short dance and Holly Harris, the youngest skater on the Australian team, looking to make her mark in the Ladies short program on Friday.