The Swedish star was a full 4.65 seconds behind second-place Nadine Fähndrich of Switzerland.
The second-best Swede was Johanna Hagström, over six seconds ahead of Svahn. In total, nine Swedes advanced from the prologue, including Olympic skiers Maja Dahlqvist, Moa Ilar and Emma Ribom.
On the men's side, six Swedes advanced. George Ersson was the best, placing seventh.
The sprint competition in Falun continues in the afternoon. Jonna Sundling, silver medalist in the Olympic sprint and gold medalist in the sprint relay, is ill and will not participate.
