Having taken his maiden pole position at the Cape Town E-Prix after beating Maximilian Guenther in their qualifying final, Fenestraz had lost out to the eventual top two of Antonio Felix da Costa and Jean-Eric Vergne over the course of the 32-lap race.
The Franco-Argentine had managed to put a move on long-time leader Cassidy to move up to third, which he looked set to hold onto until the final lap when Fenestraz - unseen on TV - hit the wall and tumbled down the order.
