American Connor Fields, Australian Sam Willoughby and defending gold medalist Maris Strombergs were among the riders to move into the semifinals of the men's BMX competition Thursday.
Fields clocked the fastest time in the first three (of five) runs during his heat to automatically qualify for Friday's semifinals.
The quarterfinals were comprised of four heats of eight riders, and only four riders advanced from each.
Like Fields, the Netherlands' Raymon van der Biezen placed first in the opening three runs of Heat 1 to get into the semis. Van der Biezen was the fastest rider during seeding runs Wednesday.
Willoughby, who won the world championship in May, and Strombergs were two of the riders to advance out of Heat 4. The Latvian Strombergs captured the first men's Olympic BMX gold four years ago in Beijing.
The United States' David Herman advanced out of Heat 3, though fellow American Nicholas Long did not.