Eggleston Motorsport driver Will Brown has opened up his 2019 Dunlop Super 2 Championship campaign with a 5th place in practice for Round 1 on the streets of Adelaide.
Tickford Racing driver Thomas Randle turned a 1:21.4397s in the final minute of the second of two practice sessions to lead the 20-car field.
Randle and MW Motorsport's Fullwood shared the first and second places across the two practice sessions, the latter fastest in Practice 1.
Fullwood went to the top of the order again towards the end of Practice 2, but was displaced by the late effort from Randle, who was ultimately 0.0757 seconds clear.
Brodie Kostecki was third in the combined order, 0.2190s adrift, having been sixth in the opening session.
Fullwood's team-mate Zane Goddard and Eggleston Motorsport's Will Brown took fourth and fifth for the day.
Triple Eight recruits Kurt Kostecki and Brenton Grove were sixth and eighth, split by Mason Barbera, while Ash Walsh was ninth.
Matt Stone Racing returnee Walsh only turned two laps in Practice 1 after glancing the Turn 8 wall.
The first 10 minutes of the day's 70 were dedicated to the five rookies in the field; Tyler Everingham, Abbie Eaton, Dylan O'Keeffe, Joel Heinrich and Justin Ruggier.
O'Keeffe was the best of them by the end of the day in 10th in the order for Garry Rogers Motorsport.
Further down the order, Everingham, Ruggier, Heinrich and Eaton finished 13th, 14th, 19th and 20th.
In the second Matt Stone Racing Commodore, British driver Eaton wound up 3.4101s off the pace set by Randle.
ARMOR ALL Qualifying will take place at 12:30pm local time on Friday, followed by Race 1 at 5:40pm local time.