Supercars championship leader Shane van Gisbergen has been battling jet lag ahead of the Darwin Triple Crown after returning from a dash to France.
The Red Bull Ampol star made his debut at the famed 24 Hours of Le Mans last weekend, living out a lifelong dream to be on the grid for the world's oldest endurance racing event.
Other Supercars drivers are fresh from three weeks off after the Winton Supersprint but van Gisbergen has been trying to reset his body clock.
The 33-year-old started way off the pace at Hidden Valley Raceway on Friday, completing 19 laps in practice one but came in only 17th fastest.
However, van Gisbergen is never down for long and hit back in the afternoon session to set himself up for another productive weekend in the Northern Territory.
Van Gisbergen won two of the three races in the Top End last year, falling just short of claiming the elusive Darwin Triple Crown title.
He holds a 281-point lead over Shell V-Power's Anton De Pasquale in the championship standings.
Van Gisbergen famously won all three races at Sandown last year after having shoulder surgery just two weeks prior to the event so some tiredness is unlikely to faze the New Zealander.
"I'm not sleeping perfect yet," van Gisbergen said after being asked about his gruelling travel schedule.
"That's part of the jet lag, but I'm getting better every day.
"Qualifying's going to be real important here because the tyre pressure is just stupidly high.
"We've just made some changes after the first one to make the car better so we'll go back to that first run and try and make that better."
Brad Jones Racing's Andre Heimgartner and De Pasquale rounded out the top-three of the second practice session.
Ford veteran James Courtney had a disastrous session after slamming the front of his Mustang into a wall.
Tickford team engineers will have a busy night working on Courtney's car, which suffered serious damage in the crash.
Earlier, Chaz Mostert topped the times as the reigning Bathurst 1000 champion seeks to make amends for disappointing rounds Perth and Winton.
After winning two of the season's first six races, Mostert has struggled since the start of the Australian Grand Prix event in April.
But the Walkinshaw Andretti United driver feels like he could return to the podium in the Northern Territory.
Fellow Commodore driver Will Brown finished second, while Ford veteran James Courtney was third fastest.
The first race of the weekend will get underway at 3.55pm AEST on Saturday.
Two races will conclude the Top End event, which is doubling as the Supercars' first Indigenous round, on Sunday.
