Riders compete during the BMX Cycling quarter final competition of the Rio 2016 Olympic Games at the Olympic BMX Centre in Rio de Janeiro, Brazil, 18 August 2016.
Luck belatedly turned Australian cycling's way at the Rio Olympics in two hours of BMX crash carnage.
As Sam Willoughby and Anthony Dean showed medal-potential form on Thursday, several key rivals bowed out in the quarter-finals.
Latvia's two-time defending Olympic champion Maris Strombergs, French reigning world champion Joris Daudet and British former world champ Liam Phillips were all eliminated as windy conditions played havoc.
Willoughby, the London Olympics bronze medallist, was the only rider to win all three of his quarter-final races.
Dean's stocks also continue to rise, with his second place and two wins confirming his medal potential.
Willoughby was asked whether it was a relief to make it through such a dramatic session unscathed.
"It's part of the process, if it was a relief I would be walking on eggshells," he said.
"I came here to win laps and that is three out of seven done.
"It's a step in the right direction."
The two Australians are into Friday's semi-finals (Saturday AEST), also run over three rounds, with the medal race to follow.
The women, featuring top Australian hope Caroline Buchanan and compatriot Lauren Reynolds, also have their semis and final on Friday.
Strombergs and Phillips crashed in the first round of their quarter-final heat, with the British rider limping off the course and not riding again.
Liam Phillips of Great Britain (R), David Graf of Switzerland (L), and Maris Stormbergs of Latvia (C) crash during the men's BMX Cycling quarterfinal competition of the Rio 2016 Olympic Games at the Olympic BMX Centre in Rio de Janeiro, Brazil, 18 August 2016.
The Latvian star continued, but failed to make the quarters on a countback.
Daudet crashed in a separate race and he finished sixth in his heat, also ending his chances.
Until now, luck had deserted Australian cycling in Rio, with a string of crashes and other problems contributing to below-par performances.
Willoughby said he had no idea that several of his rivals had bowed out of medal contention.
"All I knew was I was going up the stairs (to the start) and Metallica was blaring in my ears all day," he said.
He added the focus was to race well, but stay out of trouble.
To that end, Willoughby and Dean hit the front early in their heats and avoided any problems.
"Today with the wind out there, it was carnage," Willoughby said.
"I ran at about 80-90 all day and ticked off clean laps, and that's what today was about."
The third Australian in the men's field, Bodi Turner, rode in the same quarter-final heat that Dean won convincingly over the three rounds.
Turner finished fifth, with the top four progressing to the semis.
"Anthony has increased in the last four years, he's been a consistent podium in the US circuit," said coach Wade Bootes.
"We have a good strong bunch of guys who work together really well and tomorrow they'll go out and do their best.
"We expected him (Turner) to come here to get ready for Tokyo, but he's shown really good form in that last moto (fourth), we just would have liked to have seen that in the first two, but he's getting that learning experience."
© AAP 2016