Kotsenburg's first run of two was his best on the slopestyle snowboard course, a downhill event with a series of spectacular jumps and obstacles where style - not speed - is of the essence for the presiding judges.

Kotsenburg scored 93.5 (out of 100) in his first attempt, falling just over 10 points short of this benchmark second time around. The victory was something of a shock, as Kotsenburg was not among the seeded riders, and had to qualify for the medal competition via the earlier semifinals.

Norway and Canada also got off the mark on Saturday morning, as Staale Sandbech won silver and Mark McMorris claimed bronze. Both these competitors logged their best scores, 91.75 and 88.75 respectively, on their second runs after making major mistakes first time out. McMorris, a two-time "X Games" slopestyle champion, was considered among the favorites before the off.

The slopestyle event had made headlines prior to the Sochi opening ceremony on Friday, even, when star US snowboarder Shaun White surprisingly withdrew from the competition. White had spent a couple of days practicing on a course he described as "intimidating," and then said he would instead concentrate on the other major freestyle snowboard discipline, the halfpipe.

Early lead for Norway in medal table

Shortly after Sandbech's silver for Norway on his snowboard, the country's skiers rounded out a complete collection of precious metals from the Winter Games. In the women's 15-kilometer cross-country skiathlon, Marit Bjoergen won Norway's first gold and Heidi Weng bagged the country's first bronze. Temporarily, therefore, Norway raced to the top of the medal table with three of the first six podium places to be awarded.

Bjoergen completed the course in 38 minutes, 33.6 seconds, defending her title from the 2010 Vancouver Games, with Sweden's silver medalist Charlotte Kalla the meat in a Norwegian sandwich. Kalla and Bjoergen had pulled away from the lead pack of five skiers on the final uphill section, before sprinting a tough race to the finish.

Nicole Fessel of Germany was in the hunt for a top-10 finish until late in the race, but ultimately crossed the line in 14th.

"It was hugely tough. I was having a bit of trouble with the heat, and suffered from cramps in my calf on the last climb," 30-year-old Fessel told German public broadacaster ARD after the race.

Biathlon, cross-country skiing, freestyle skiing and speed skating competitions are all slated for the official opening day of competition on Saturday - although some athletes began their Olympic missions prior to Friday evening's opening ceremony.

msh/jlw (dpa, Reuters)