Adrien Simon was fastest for the second practice session in a row ahead of this weekends Malaysian V-Prix, but in much different conditions to that of Phillip Island.
Torrential rain fell for around half the session, letting up slightly and then stopping towards the end, resulting in a flurry of fast times and a rapidly changing leader board in the dying minutes.
It was the reigning champion who eventually came out on top by just over two tenths from Nathaniel Powers, with Johan Halvosen and Olen Inman both finding themselves back up the sharp end of the grid for the first time this season after disappointing races in Australia.
The biggest surprises of the session were the lack of pace from renowned rain master Felix Beyer, and the lacklustre performance from Enrique Ruiz as the pair ended 17th and 20th respectively.
While a wet session rarely provides much useful information to go on, rain is forecast for tomorrow's qualifying session so the teams will likely have got some useful data from the wet running.
See full classification below: