Sweden's Louise Lindström won the silver and Hedda Östberg Amundsen of Norway landed the bronze.
Earlier in the championships, Poland’s Monika Skinder won the gold and teammate Karolina Kaleta grabbed the bronze in the women’s cross-country skiing sprint classic.
Hundreds of young athletes took part in the event in Finland despite the coronavirus pandemic.
Marcisz, 20, is an up-and-coming cross-country skier who grew up near the southeastern Polish town of Krosno.
Nasza mistrzyni ❤ Izabela Marcisz 🥇🇵🇱🥰
Posted by Polski Związek Narciarski on Friday, February 12, 2021
(gs/pk)
Source: IAR