The Dick Johnson Racing driver had several stints on top of the times throughout the half-hour sessions, including right at the start when the times were still in the 1m09s bracket.
Having been shuffled down the order he then rocketed back to the top with a little over 10 minutes to go with a 1m08.147s.
Five minutes later Davison was pipped by Shane van Gisbergen, the Kiwi going one thousandth of a second faster.
But Davison was able to hit back on a final green tyre run, becoming the first driver into the sevens for the weekend with a 1m07.808s.
Chaz Mostert ended up second fastest with a 1m08.027s on his final run, which put him between the DJR cars, with Anton De Pasquale third.
Mark Winterbottom was another late improver as he jumped up to fourth, while van Gisbergen was shuffled back to fifth.
Brodie Kostecki was sixth fastest ahead of David Reynolds, Will Brown and Macauley Jones.
Practice continues with a half-hour session dedicated to the Bathurst 1000 co-drivers at 3:20pm local time.
