Justyna Kowalczyk

Justyna Kowalczyk reacts after winning the women's cross-country 10-kilometer classical race on Thursday at the Sochi Olympics. (Harry How / Getty Images / February 13, 2014)

SOCHI, Russia -- Justyna Kowalczyk of Poland dominated her favorite event at the Sochi Olympics on Thursday, winning the women's cross-country 10-kilometer classical race despite skiing with a fractured foot.

Kowalczyk led from the first intermediate time in the interval start race and only increased her lead as the race went on. She finished in 28 minutes 17.8 seconds, beating silver medalist Charlotte Kalla of Sweden by 18.4 seconds.

Therese Johaug of Norway took bronze, 28.3 seconds behind.

Four-time Olympic champion Marit Bjoergen tried to keep up with Kowalczyk but tired toward the end and was fifth, 33.4 behind.

Kowalczyk injured her left foot last month and posted a photo of an X-ray on her Facebook page this week showing a small fracture, but said it wouldn't stop her from competing.

Some lower-ranked skiers had yet to finish.