Peter Hackett and Dominic Storey banked the fastest time in opening practice ahead of this weekend’s Hampton Downs 500.
Mixed conditions dominated proceedings, which started damp before drying through the middle of the 60-minute session.
The Eggleston Motorsport Mercedes-AMG GT3 duo made the most of the dry conditions to record their best lap, which proved 0.167s quicker than the Hot Wheels Car Care Products Porsche 911 GT3 R of Liam Talbot and John Martin.
Setting identical times were the Wall Racing Lamborghini Huracan GT of Adrian Deitz and Cameron McConville, and the Blue Line Plumbing Audi R8 LMS GT3 of locals Andrew Fawcett and Jonny Reid.
Having set their time first, it was the Deitz/McConville Lamborghini which was classified third fastest in the ultra-competitive session courtesy of setting their time first.
The top five was rounded out by Phillip Island 101 winners Tony Bates and Daniel Gaunt in the KFC/MoveItNet Audi R8 LMS GT3, making it two Audis in the top five.
Australian GT Championship points leader Fraser Ross was sixth fastest in the McElrea Racing run Total/Opti-Coat McLaren 650S GT3 he’s sharing with Duvashen Padayachee.
The duo were once place up on Australian Endurance Championship leaders Max Twigg and Tony D’Alberto in the WM Waste Management Mercedes-AMG GT3.
Rain in the closing minutes of the session limited running, while some elected not to venture out in the opening minutes as the rain tumbled.
With just 2.4s covering the field after opening practice it promises a hotly contested qualifying session on Saturday morning, with Driver A taking the wheel at 0930 before the Driver B session at 1000.
Those sessions will determine the grid for the all-important 30-lap qualifying race, which carries 20 valuable championship points for the winner, which begins at 1500 on Saturday.
Fans can follow along with all the action via Australian GT’s Facebook and Instagram pages, with video updates throughout the weekend.
Result: Hampton Downs 500, Practice 1
| # | Team | Car | Drivers | Time |
| 63 | Eggleston Motorsport | Mercedes-AMG GT3 | Peter Hackett/Dom Storey | 1:32.401 |
| 911 | Hot Wheels Car Care Products | Porsche 911 GT3 R | Liam Talbot/John Martin | 1:32.568 |
| 6 | Wall Racing | Lamborghini Huracan GT3 | Adrian Deitz/Cameron McConville | 1:33.007 |
| 10 | Blue Line Plumbing | Audi R8 LMS GT3 | Andrew Fawcett/Jonny Reid | 1:33.007 |
| 24 | KFC/MoveItNet | Audi R8 LMS GT3 | Tony Bates/Daniel Gaunt | 1:33.245 |
| 59 | Total/Opti-Coat | McLaren 650S GT3 | Fraser Ross/Duvashen Padayachee | 1:33.766 |
| 8 | WM Waste Management | Mercedes-AMG GT3 | Max Twigg/Tony D’Alberto | 1:34.007 |
| 7 | Local Legends Beef Jerky | Aston Martin Vantage GT3 | Tony Quinn/Andrew Waite | 1:34.034 |
| 1 | Valvoline | Audi R8 LMS GT3 | Geoff Emery/Garth Tander | 1:34.051 |
| 100 | BMW Team SRM | BMW M6 GT3 | Michael Almond/Steve Richards | 1:34.466 |
| 222 | Scott Taylor Motorsport | Mercedes-AMG GT3 | Scott Taylor/Craig Baird | 1:34.869 |
