Paul Dumbrell is off to a flying start for his Wilson MedicOne Enduro campaign, going straight to the top of the time sheets for the first practice session of the weekend.
The Royal Wolf driver and series leader set the pace with a 2:10.39 around the legendary circuit, with ENZED's Cameron Waters adrift by 0.19secs.
However, the session was interrupted twice by red flags, with the latter causing the session to end with only three minutes to go.
Aaron Tebb caused the first red flag, succumbing to the Chase and getting bogged in the sand trap.
The second and ultimate red flag was caused when Peter Rullo's Falcoln also struck bad luck at the Chase, suffering heavy damage to the front of the Matthew White-prepared Ford.
The two front runners, who will be on double-duties this weekend, were followed by title contender Ash Walsh in third, who was consistently at the top end of the time sheets throughout the 40-minute session.
The kiwis locked out positions from fourth to sixth, with Chris Pither - fifth - separating the two drivers also running in the Super Black wild card,Andre Heimgartner and Ant Pedersen.
Paul Morris was seventh fastest in the session, followed by Tony D'Alberto, who is co-driving with Josh Kean for the Wilson MedicOne Enduro on Saturday.
Eggleston Motorsport's Gary Jacobson, and Geoff Emery rounded out the top ten.
Aaren Russell, who clinched his maiden podium at the last round at Queensland Raceway was on the fringes of the top 10 in 12th, while Bathurst rookies Macauley Jones, Todd Hazelwood and Dan Day were 14th, 16th and 21st respectively.
Andrew Jones failed to set a competitive lap in the session, remaining in the pits with crews attending to his Freightliner Commodore.
The Dunlop Series will return to Mount Panorama for the second practice session ahead of the Wilson MedicOne Enduro at 10.25am tomorrow.