Norway claimed a clean sweep in the men's sprint classic in Ruka as Johannes Hoesflot Klaebo led a Norwegian 1-2-3-4.
Tiril Udnes Weng secured bronze on a bumper day for Norway in the women's sprint in Finland as Swedish pair Emma Ribom and Johanna Hagstroem came home first and second.
In the opening event of the cross-country season, reigning champion Klaebo topped his quarter-final, finishing just behind overall leader Calle Halfvarsson.
Paal Golberg leads a Norwegian 1-2-3-4 in Lillehammer mass start
Klaebo completed the course 0.3 seconds ahead of his nearest challenger in the semi-finals before taking the win by 1.66 seconds from countryman Even Northug in a late attack.
Paal Golberg rounded out the podium with a fourth Norwegian, Erik Valnes just behind them as last season's overall sprint champion Richard Jouve of France failed to make it out of the semi-finals.
In the women's event, Ribom was dominant in the qualifying stages on her way to a maiden victory.
The 24-year-old was top of the pile after both the quarter-finals and semi-finals before claiming gold in a time of 2:49.22, 0.91 seconds faster than her fellow Swede Hagstroem.
She benefitted from a fall to her team-mate, race leader and 2021-22 sprint champion Maja Dahlqvist, who took a tumble in the closing stages to deny Sweden a clean sweep as Weng beat out home favourite Jasmi Joensuu of Finland for the bronze.
Cross-Country Skiing
Golberg leads a Norwegian 1-2-3-4 in Lillehammer mass start
Karlsson storms to victory in women's cross country mass start in Lillehammer