Slade and van Gisbergen came to blows near the end of this morning's second qualifying session in what seemed to be a miscommunication between the drivers.
Van Gisbergen was on a fast lap and felt Slade – on a warm-up lap – was going to let him through at Turn 6.
Slade, however, didn't realise van Gisbergen was on a flyer and closed the door.
The resulting contact left both cars damaged, while van Gisbergen lost a lap that had been purple in the first and second sectors and had to settle for third on the grid.
While Slade initially claimed he'd been "bombed" by van Gisbergen, stewards have since ruled in favour of the Kiwi.
Slade has been given a three-place grid penalty for the incident and been stripped of his best lap, which had left him 10th on the grid, for causing a red flag.
"A review of broadcast footage revealed that car #3 had aborted its flying Lap at Turn 4 but failed to get out of the path of car #97 at the entry to Turn 6 when car #97 was on a flying lap," read the stewards report.
"Because car #3 caused the red flag, its fastest time in the session is deleted in accordance with the rules such that the three grid spot penalty is applied by reference to the next fastest time set by car #3 in the session."
Chaz Mostert was also penalised for impeding Andre Heimgartner at the hairpin during that session. He will lose one spot and start Race 3 from 20th.
