The three-time Bathurst winner came into the session with nothing but green tyres in his bank, based on his Audi having only just arrived in the country.
He wasted little time putting that advantage to good use, Tander dropping into the 1m39s, and then 1m37s before anyway else had broken under the 1m40s mark.
An impressive opening run ended with a 1m37.222s, which proved to be the session-topping time.
The closest anyone got to Tander's time was Alfa Romeo driver Dylan O'Keeffe, who fell just 0.16s short with his final lap.
John Martin was the best of the Wall Racing Honda drivers, ending the session eight-tenths down in Tander in third.
Leanne Tander was an impressive fourth quickest, enjoying a similar tyre advantage to her husband Garth, while Supercars regular Andre Heimgartner was fifth in the Kelly Racing Subaru.
Tony D'Alberto was sixth in his Wall Honda, Jason Bright seventh in the Alliance Autosport VW, and Nathan Morcom the best of the HMO Hyundais in eighth.
Aaron Cameron (MPC VW) and James Moffat (Garry Rogers Motorsport Renault) rounded out the Top 10.
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