Canada's McMorris left bemused after Olympic slopestyle slump
Mark McMorris of Canada soars to second place in the men's Snowboard Slopestyle at Winter X-Games 2014 Aspen at Buttermilk Mountain on January 25, 2014 in Aspen, Colorado - by Doug Pensinger
The 20-year-old, who won gold at both the 2012 and 2013 X-Games, could finish only seventh in his heat with a best score of 89.25 points, meaning he will have come back on Saturday for the semi-finals in his bid to reach the final.
"I just didn't think my run was worth such a low score, I didn't see what was that much more insane about their runs but it's a judged sport," he said.
"I'm just happy with the way I rode and I'll try to figure something else out for Saturday for the semi."
Only the top four from each heat went straight through to the final while all the rest have a second chance when four more will emerge from Saturday's semi-final to complete the 12-man final field.
McMorris's score would actually have been good enough to qualify from the first heat.
Norway's Staale Sandbach won that with 94.50, with Finland's Peetu Piiroinen second on 90.75.
But the second heat was more competitive with reigning 2014 X-Games champion Maxence Parrot of Canada top-scoring with 97.50 while 2013 slopestyle and Big Air world champion Roope Tonteri of Finland managed 95.75.
The other four final qualifiers were Norway's Sven Thorgren (94.25), Gjermund Braaten of Norway (91.25), Canada's Sebastien Toutant (87.25) and Jamie Nicholls of Great Britain (86.75).