Nick Percat set the pace on a quiet opening day for the Carrera Cup Australia at Winton Motor Raceway.
The Melbourne-based South Australian topped the one and only practice session of the day, run in the dry of the late afternoon.
Percat, a former race winner in Formula Ford and the Dunlop Series at Winton, enters the weekend third in the standings behind Craig Baird and Warren Luff.
Steven Richards was just 0.23s adrift of Percat at the end of the 20 minute hit-out, with Baird, Luff and Shae Davies completing the top five.
Former Aussie Racing Car series winner Adam Gowans managed 10th on his debut in the Porsche class with Team Kiwi Racing.
Rusty French, competing in his car that was set to be campaigned by GT3 Cup front-runner Michael Almond before a deal fell through, was 18th.
The Aussie Racing Car Series and Australian Formula Ford Championship were also on track today.
Kyle Klews led home Maurice Masini by a comfortable 5.5s in the opening ARC race, while Macualey Jones proved fastest at the end of two Formula Ford practice sessions.