Romania's Vlad Dascalu and Haley Batten of the United States were the victors in the under-23 Olympic-distance races at the International Cycling Union (UCI) Mountain Bike World Cup event in Nové Město na Moravě.
Dascalu completed the course in the Czech town in 1min 14:24secs, holding off Switzerland's Philipp Colombo who finished second in 1:14:25.
Denmark's Simon Andreassen was third in 1:14:34.
"Everything went perfectly today," Dascalu said.
"I was feeling great from very morning and I knew I had strong legs."
Batten was the winner in the women's race, recording 1:13:38.
Germany's Ronja Eibl was second with 1:14:06, while Austria's Laura Stigger ended up in third with 1:14:58.
The elite competition in the Olympic-distance race takes place tomorrow.