Ford’s Chaz Mostert was the quickest driver in opening practice on Friday for the Sydney SuperSprint Supercars event.
The 2014 Bathurst champion, who won two of three races at Sydney Motorsport Park in 2015, clocked a fastest lap of one minute and 30.3345 seconds.
Holden’s Tim Slade (1:30.4466) and Nissan’s Michael Caruso (1:30.6858) rounded out the top three in an hour-long session, which was affected by rain in its dying minutes.
Championship leader Jamie Whincup was sixth-fastest with rivals Shane van Gisbergen (8th), Mark Winterbottom (10th) and Craig Lowndes (12th) trailing the Holden star.
Mostert is yet to win a race in 2016 after recovering from serious injuries he suffered last year in a qualifying crash at Bathurst.
Holden’s Lee Holdsworth made his return to action on Friday, driving on the track for the first time since breaking his pelvis in a crash at Darwin in June.
“I feel good,” Holdsworth said.
“Hopefully a bit more running in the second session. I feel quite comfortable.”
Friday’s action wraps up with a second hour-long practice session from 4pm.