Britain's Liam Phillips crashed and Shanaze Reade finished sixth as Maris Strombergs of Latvia and Mariana Pajon of Colombia won the men's and women's Olympic BMX titles at the London 2012 Velopark.
After Reade finished well behind, Phillips, who suffered a fractured collarbone at May's BMX World Championships in Birmingham, tumbled to the tarmac on the penultimate turn.
The 23-year-old from Burnham-on-Sea appeared to start well, but finished eighth as Strombergs successfully defended his title. World champion Sam Willoughby of Australia was second with Colombia's Carlos Oquendo third.
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