Mostert produced a time of two minutes, 5.2056 seconds in the opening Bathurst 500 practice session before bettering that effort later in the day with a 2:04.7817.

"We obviously want to try and get the confidence up nice and early in the weekend. Something about practice in round one with this team we seem to shine always, like last year," Mostert said following the opening session.

"The car felt pretty good, we made some changes for that session, it felt like it was positive. The feedback of the car and the tunability us something we didn't quite have last year, which is something that seems to be working today, but we'll see what happens in the next one and keep trying to build confidence in sessions to come.

"We didn't really talk about where we needed to go quicker throughout the session. This place is one of the confidence-building places; if the car gives you feedback, gives you confidence, generally you'll find the most amount of time across the top of the car is stable.

"It felt like we made some little improvements and that helped, but green tyres, how you get them in - I had a pretty clean out lap, I could bring the tyres in when I wanted."

The opening session ran smoothly until just past the halfway point when Supercars rookie Will Brown, sitting third at the time, crashed at The Esses and brought out the red flag.

In a rarely seen incident at that section of the track Brown clipped the inside wall while turning left, sending him into the opposite wall and damaging the entire front end of his Erebus Motorsport Commodore.

It was a rough introduction to the main game for last year's Super 2 series runner-up but Erebus boss Barry Ryan brushed off the incident, saying that Brown was told to "go out have fun and go fast".

Shane van Gisbergen's early lap time of 2:06.5262 stood for more than 45 minutes before a flurry of quick times arrived in the final laps of the session.

Mostert climbed to the top with his 2:05.2056, putting him clear of Cam Waters (2:05.7054) and Walkinshaw Andretti United teammate Bryce Fullwood (2:05.8534).

Session two got off to a nightmare start for Brad Jones Racing when Macauley Jones beached his Commodore at The Chase and Todd Hazelwood's car began to smoke heavily after running wide at turn one.

"It feels like it has just ripped the line off the steering rack," Hazelwood said of his incident.

"That's obviously lots of pressure, it has filled the whole cabin with smoke. It looks quite dramatic, but hopefully it is a quick fix and we can pressurise the line."

With just over 20 minutes remaining in the session Mostert went quicker than his practice one mark with a 2:05.1039 and held the lead for some time.

Waters was the first driver of the day to get below 2:05 with his 2:04.7928 inside the last four minutes of the session but Mostert got top spot back immediately with his 2:04.7817.

Scott Pye was third fastest in the session with 2:05.3896.

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