Norway's Maiken Caspersen Falla snatched her maiden Winter Olympic title when she won the cross-country sprint event after compatriot, defending champion and hot favourite Marit Bjoergen crashed out in the semi-finals.
Bjoergen, who won the individual sprint in Vancouver four years ago, was seeking her fifth Olympic title but failed to make the final where Falla was never threatened.
Team mate Ingvild Flugstad Oestberg produced a late surge to catch Slovenian Vesna Fabjan on the line and take silver by two hundredths of a second, leaving Fabjan with a second successive bronze in the event.
Bjoergen, who won the skiathlon on Saturday, had taken third place in the qualification round as several skiers fell on the 1.3km circuit on melting snow in warm conditions at the Laura Biathlon and Cross-country Complex.
Elsewhere, Ola Vigen Hattestad of Norway won his first Olympic title in a chaotic cross-country men's sprint.
Teodor Peterson of Sweden took silver and another Swede, Emil Joensson, came through to take the bronze after a tricky right-hand bend on a descent sent three skiers tumbling.
Joensson, Norwegian Anders Gloeersen and Russian Sergey Ustiugov fell and when the snow settled it was the host nation athlete who was quickest to get back on his skis.
However, more misfortune followed for Ustiugov as he realised he had broken a ski pole and watched Swede Joensson claim third place.
Norwegian Petter Northug's miserable Olympics continued when he was eliminated in the semi-finals. Several other top contenders, including 2010 sprint champion Nikita Kriukov of Russia, were eliminated before the final.
Canada keep winning
Dara Howell continued Canada's dominance at Rosa Khutor Extreme Park, soaring to Olympic gold in women's slopestyle skiing.
Howell posted a score of 94.20 during her first run of the finals, trouncing the rest of the field on a warm and sometimes frightening day down the slushy slopestyle course.
Devin Logan of the U.S. took silver. Canadian Kim Lamarre earned bronze.
Canada has claimed seven medals in four days of snowboarding and freestyle skiing, including three events in which they took two of the three spots on the podium.
Howell's triumph was tempered by a series of scary crashes, including one by teammate Yuki Tsubota that ended with Tsubota being carried of the mountain on a stretcher.
Lee Sang-hwa of South Korea successfully defended the women's Olympic 500 metres speed skating title at the Adler Arena.
Lee clocked an Olympic record 74.70 seconds over her two 500m runs. Olga Fatkulina of Russia claimed silver, finishing 0.36 seconds behind the Korean, with Margot Boer of Netherlands taking bronze.