In ideal conditions with temperatures around -5 degrees, AIS Scholarship holders Michelle Steele, Lincoln-Smith and Lucy Chaffer finished 12th, 13th and 18th from the 23 sliders, with victory going to Great Britain's Shelley Rudman.
With consecutive victories, Rudman is now only 11 points behind World Cup leader Anja Huber, from Germany, with Canada's Melissa Hollingsworth in third place after taking second in Switzerland.
St. Moritz is the birthplace of skeleton and is the only non-refrigerated track that hosts international competitions. It hosted the 1928 and 1948 Winter Olympics, and has hosted the FIBT World Championship a record 17 times.
After top 10 finishes in the first five rounds of this season's World Cup, Lincoln-Smith's consistency has paid off, but she was disappointed with 13th in St. Moritz. Lucy Chaffer maintains her ranking at 17th.
After a delayed start to the season, Queenslander Michelle Steele is improving with every event and her 12th place in St. Moritz has her eyeing top 10 results as the season moves towards the World Championships in Germany next month.
Australia's sliders are now gearing up for the World Championship in Germany at the end of February. Before then, however, they have the final event of the World Cup series, in Cesana, Italy, to contest on February 4.
All three women will be hoping for improved performances, and to move further up the final World Cup standings.