The session, limited to Bronze-ranked drivers, got off to an interrupted start, the red flag making its first appearance of the weekend a few minutes in when Keith Kassulke looped the #52 MARC V8 at The Cutting.
Once the session went green it was Brad Schumacher (#55 Schumacher Audi) and Kenny Habul (#75 SunEnergy1 Mercedes) that initially battled it out at the top.
That battle proved to be incredibly tight, Habul's 2m06.135s leading Schumacher's 2m06.139s with a little over 10 minutes to go.
It was at that point the pair were jumped by Valentino Rossi in the #46 WRT BMW, the MotoGP legend – and Bathurst rookie – having been granted a dispensation for the session despite his Silver driver ranking.
Rossi was still leading when the session was red-flagged again inside the last 10 minutes after Marc Cini hit the wall at The Cutting in the #9 MPC Audi.
When the action resumed Bathurst local Schumacher made his play for top spot, jumping ahead of Rossi with a 2m05.518s right at the flag.
But Rossi was able to respond, the MotoGP legend reclaiming top spot with a 2m05.448s on his final run.
Habul was unable to improve in the closing minutes and had to settle for third ahead of Liam Talbot in the #65 MPC Audi.
Yasser Shahin was fifth fastest in the #777 MPC Audi, one spot clear of GT World Challenge Australia rival Prince Jefri Ibrahim in the #99 Triple Eight Mercedes.
Andrew Fawcett (#10 International Motorsports Audi) and Marcelo Zalloua (#44 Valmont Racing Mercedes) were next while Tony Bates (#24 Volante Rosso Mercedes) and Geoff Emery (#222 Scott Taylor Motorsport Mercedes).
Practice continues with another Bronze-only session at 2pm local time.
