* Norwegian wins slopestyle gold
* Sochi bronze medallist Goepper clinches silver
* Beaulieu-Marchand takes surprise bronze
* Eight skiers score more than 90 points in qualification (Adds detail, quotes)
By Jack Tarrant
PYEONGCHANG, South Korea, Feb 18 (Reuters) - Norway's Oystein Braaten struck early with a brilliant first run as he claimed gold in the Olympic freestyle skiing men's slopestyle event on Sunday.
American Nick Goepper improved on his bronze from Sochi four years ago with a silver medal as Canada's Alex Beaulieu-Marchand claimed a surprise third place.
The event was a high quality one, the best ever according to Goepper, with eight riders scoring more than 90 points just to qualify for the 12-rider final.
Braaten laid down an early marker in the final, scoring 95.00 on his first run and as most of his rivals failed to match the Norwegian's crisp and clean routine, his impressive total was good enough to hold on to top spot through all three rounds.
"It feels amazing to win," Braaten told reporters.
"It has been a dream just to get to the finals, through such heavy qualifying, then landing the best run I have ever done in the first run of the final... I am speechless."
Goepper left it late but saved his best for last, jumping up from nowhere into second place with a 93.60 effort on his final run.
Speaking after the final, Goepper said he changed his initial plan once the high quality of the field became evident.
"I made a couple of minor mistakes (on the first two runs) so I knew that even if I landed the final jumps I wouldn't be in medal contention so I decided to conserve my energy and lay it all out on the third run," the 23-year-old said.
"I knew that the calibre of my third run would put me in the top three. There were some really good guys still to drop, so it was a nail-biting moment waiting at the bottom."
His team mate Gus Kenworthy, a silver medallist four years ago as part of a United States podium sweep, failed to record a clean run and finished 12th and last in the final.
Sweden's Oscar Wester, who top-scored in qualifying with 95.40, was another medal candidate who failed to deliver a clean run in the final.
Beaulieu-Marchand, 49th in the World Cup rankings, was a surprise bronze medallist, his 92.40 second run leaving him looking stunned as he stood on the podium.
The 23-year-old said the Olympic final had drawn out the best performance of his career.
"I think I am a third-place kind of guy," joked Beaulieu-Marchand, who has never finished higher than third at a World Cup event. "Today was the best day of skiing I have ever had in my life."
The Canadian edged Great Britain's James Woods into fourth place by just 1.40 points.
Woods was the only competitor to score 90 points or over on multiple runs but as only the top score counted towards the final result, he missed out on claiming a second skiing bronze for Britain at these Games.
Compatriot Izzy Atkin won bronze in the women's ski slopestyle on Saturday. (Reporting by Jack Tarrant; Editing by John O'Brien)