Sage Kotsenburg won the men's snowboarding slopestyle title at the Sochi Games on Saturday, the first gold medal of the 2014 Winter Olympics.
Kotsenburg took the gold with a best score of 93.50, with Norway's Staale Sandbech taking the silver and Canadian Mark McMorris the bronze.
Sochi 2014 medals (top 3)
Marit Bjoergen won the women's 15-kilometre skiathlon, giving the Norwegian cross-country skier her fourth career gold medal.
Canadian teenager Justine Dufour-Lapointe claimed a shock gold medal in the mogul freestyle skiing as sisters won the top two medals in the same Winter Olympics event for the first time since 1992.
She and older sibling Chloe stunned overwhelming favourite Hannah Kearney
in the third run of the final under the bright lights at the Rosa Khutor Extreme Park to leave the tearful defending champion with a bronze.
"It just totally rocks. It is just really amazing," Justine, 19, said.
"I really gave it my all. I felt the pressure, but I tried to just put that away and I said, 'You know what, I'm going to roar and people will see me and remember who the real Justine is'."
Hopes of a family podium sweep had disappeared when the third sister, Maxime, went out after the second run of the final but her sisters would not be denied in the final six-woman showdown.
Ole Einar Bjoerndalen of Norway won the men's biathlon 10km sprint gold medal. Austrian Dominik Landertinger took silver and Czech Jaroslav Soukup won bronze.
Sven Kramer of the Netherlands opened the Sochi Games speedskating competition in flying style by successfully defending his 5,000 metres title in an Olympic record time at the Adler Arena.
Kramer clocked six minutes, 10.76 seconds over the distance, with compatriots Jan Blokhuijsen claiming silver and Jorrit Bergsma the bronze to make it a Dutch clean sweep.
Elsewhere, the United States eased past Finland 3-1 as the women's ice hockey competition at the Sochi Olympics got off to a familiar start with one-sided victory.
The United States and Canada have won every gold medal since women's ice hockey joined the Winter Games progamme in 1998 and the Americans signaled they are once again ready to challenge for top spot with a clinical victory.