Chaz Mostert has pipped former Tickford Racing teammate Cameron Waters in a tight second practice at the Repco Mt Panorama 500.
Mostert fired his #25 Walkinshaw Andretti United entry to the top with just under three minutes remaining, unseating Waters at the top.
The 2014 Bathurst 1000 winner was at home at Mount Panorama on Friday, first rising to the top with 27 minutes remaining with a 2:05.103s.
With four minutes left on the clock, Waters hit the front in his #6 Monster Energy Mustang with a 2:04.792s.
However, not content with his pace, Mostert lowered the marker once more to put 0.011s on his old stablemate.
The session began in high drama for Brad Jones Racing, with Todd Hazelwood, Macauley Jones and Nick Percat all striking trouble within seconds of each other.
Shortly after Hazelwood pulled his car over across the top of the mountain with a suspected steering rack issue, Percat bowled a wide at the Chase, and was quickly followed in by Jones at high speed.
Jones' car was returned to the lane, and he managed to return to the session.
Midway through the hour-long session, Team 18's Scott Pye hit the front with consecutive laps in the 2:05s bracket before Mostert claimed top spot.
Both Team 18 cars were in the top five with eight minutes to go, with Mark Winterbottom rising to fifth, before teams bolted green tyres onto their cars.
In the end, it was Mostert and Waters lighting up the time sheets, with the former making it two topped sessions in a day.
Cars will return to the track at 9:05am AEDT on Saturday for ARMOR ALL Qualifying for Race 1 of the new season.
This weekend's event will be broadcast live on Foxtel and the Seven Network, and will be streamed on Kayo. Check out the full TV schedule here.