KRASNAYA POLYANA, Russia (AP) -- If a foot fracture couldn't stop Justyna Kowalczyk, a bit of sunshine certainly wasn't about to.
Kowalczyk ignored the pain in in her injured foot and the warm weather beating down on the women's cross-country skiers Thursday to win Olympic gold in the 10-kilometer classical-style race.
As her rivals tired in the heat, Kowalczyk showed exactly why this is her signature event, powering forward relentlessly toward the finish line to finish in 28 minutes, 17.8 seconds. Silver medalist Charlotte Kalla of Sweden was 18.4 seconds back, while Therese Johaug of Norway took bronze, 28.3 seconds behind.
''It's something big for me because I broke my foot two weeks ago,'' said Kowalczyk, who wept during the flower ceremony.
''It was only tears of joy,'' she said. ''I think it was the hardest 10K of my life, especially the last big uphill. I was fighting with my body. In the last 30 meters I was almost walking. I was so tired.''
This was always supposed the best chance for gold for Kowalczyk, a four-time overall World Cup winner who specializes in classical-style skiing. But then she injured her left foot in January, and suddenly it was unclear whether she'd be able to live up to her status as favorite - especially after she posted an X-ray on her Facebook page this week showing a fracture.
Kowalczyk said she took a strong pain killer before the race that numbs the foot for three hours.
''I felt an ache in my foot, but I overcame it,'' she said. ''We knew what we were here for. It was unlucky that it happened to me. Everything was going wrong, but I am not one of these people who give up.''
She probably won't mind the pain too much after earning her second career gold medal, having won the 30K classical race in Vancouver four years ago.
That time, she beat Marit Bjoergen of Norway in a tight sprint finish. On Thursday, there was never any drama as no one could keep up.
Bjoergen, who won her fourth Olympic gold on Saturday in the skiathlon, was only 1.9 seconds back after 2.3 kilometers, but that gap grew to 9 seconds by the halfway point and the Norwegian simply ran out of steam after that. She finished fifth, 33.4 behind.
''I collapsed,'' Bjoergen said. ''Why, I don't know.''
A lot of the skiers struggled with the heat, as the temperature was 12 degrees C (54 F) at the start - by cross-country standards, an absolute heat wave. Several skiers used short-sleeved shirts, with American duo Sophie Caldwell and Sadie Bjornsen going without any sleeves at all.
''The conditions are pretty crazy,'' Caldwell said. ''It's definitely the warmest and softest I've skied in in a long time.''
Bjoergen wore a normal race suit, and said it was tough to cope with the heat.
''I was dressed as lightly as possible and I only wore that because I had to have something on,'' she said.
Kalla won the 10K race in Vancouver when it was a freestyle event, and showed again that she is now also among the best classical-style skiers. She took silver in the opening 15-kilometer skiathlon as well.
''I think it's one of the toughest races I've ever done; it's altitude and it's hot and wet,'' Kalla said. ''I didn't feel I had the best speed but it was the same for everyone.''
The race also featured a number of lower-ranked skiers going out after the favorites, with some trudging slowly through the mushy snow in the sunlight.
Farzaneh Rezasoltani of Iran was more than 14 minutes behind Kowalczyk, while Ivana Kovacevic of Serbia was last, going so slowly up the final hill that race officials could walk alongside her. She finished more than 17 minutes behind.
Johaug thought she was headed for a second fourth-place finish at the games, but ended up with bronze as Bjoergen faded.
''It's possibly one of the toughest races I have ever been through but I'm really proud of myself,'' Johaug said.