Olsson is one of the world's best freeskiers - he has won nine Winter X Games medals - but also competes in the pure speed discipline of alpine skiing as he attempts to make the Winter Olympics.
He clinched the top spot in yesterday's race with the fastest combined time of 1min 29.21sec, edging Norwegian Leif Kristian Haugen into second by 0.16sec.
Swede Niklas Rainer was third in 1min 29.48sec.
Allie McGlinn, of Queenstown, continued her recent impressive form and finished second in the women's race, 0.57sec behind winner Kristine Haugen, of Norway.
Haugen's combined time of 1min 32.07sec shaded McGlinn's 1min 32.64sec, while Australian Emily Bamford was third in 1min 34.28sec.
Angus Howden, of Wellington, was the top-ranked New Zealander in the men's competition, placing 7th.
The Elite FIS series is run by the Treble Cone Racing Academy, whose ski team members include both men's and women's winner Olsson and Haugen.
TCRA director Guenther Birgmann said having athletes win both the men's and women's events at the same venue was a major step for the academy.
TCRA members also placed six athletes in the top 15 men's and four in the top 15 women's, he said.
The FIS Elite series concludes today with the slalom race at Treble Cone.
Some of the world's top big mountain skiers and boarders are residing in Lake Hawea while they wait for the perfect back-country conditions for the World Heli Challenge during the next two weeks.
About 36 skiers and snowboarders have entered the helicopter-accessed event, which will be held in the mountain ranges around Makarora and in Mt Aspiring National Park.
The three event days consisting of the "big mountain", "freeride" and "downhill" competitions need good weather conditions to allow helicopters to fly into the mountains.
The event has a two-week window which started yesterday, although ongoing stormy weather conditions meant the action was put on hold.
