The BMX pile-up in the first run of heat three resulted in seven riders – everyone except for New Zealand’s Marc Willers – crashing from their bikes.
Willers alone shot past unhindered, claiming victory in the heat.
Australia saw two of its riders progress to the semi-finals: world champion Sam Willoughby and a battered Khalen Young, who was involved in the BMX crash. Both are through to the next level of the Olympic competition.
Britain’s Liam Phillips is also through to the semi-finals although he had a tough time keeping up with gold medal favourite America’s Connor Fields in the first three runs of their quarter-final heat.
16 riders are through to Wednesday’s qualifier, including Holland’s Raymon van der Biezen and Latvia’s reigning Olympic champion.
Olympic BMX (crash) pictures
Today’s Olympic BMX quarter-final begins
Things go wonky for the seven BMX riders involved in this pile-up
Jelle Van Gorkom of Netherlands, Maik Baier of Germany, and Tory Nyhaug of Canada crash
Joris Daudet (L) of France goes to ground as the pack crash