Usual frontrunners Brown and Mostert both hit trouble on their critical runs in the second of two qualifying sessions earlier today, which left them stranded towards the bottom of the times.
Brown was only 18th fastest after a second lap while Mostert opted for a third lap as he tried to get off the very bottom of the timesheet.
It was on that third push lap that he came across Brown, who was on a cool-down lap, at Turn 7.
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The pair made light front-to-rear contact as Mostert was delayed, the Walkinshaw Andretti United star remonstrating with Brown once able to get past.
Officials have since deemed Brown at fault, which means he will start Sunday’s race from 21st, while Mostert will start last.
