After being robbed of a potential pole time mid-way through the session when a beached car caused a red flag, Campbell re-grouped to bang out a time of 1:31.049s, 0.188s faster than second-placed Italian rookie Mattia Drudi.
Championship leader Michael Ammermuller, who has won all three races this season, was a further 0.016s back in third, while Campbell's Fach Auto Tech team-mate Josh Webster was fourth with a 1:31.337s.
The pole was Campbell's third in five races this season after he qualified first for both races on debut during the Barcelona double-header in May.
To make the performance even sweeter, his mother Angela, aunt Teresa, and grandmother Sharon made a trip from Warwick in regional Queensland and were watching the performance from the grandstands.
Campbell was one of the last cars out of pit lane, but by his fourth lap had done enough to put him fourth on the time sheets.
He was up on Drudi's time by 0.2s at sector two on his next lap when the red flag came out.
“To miss out on the lap earlier because of the red flag was not ideal, but the car felt good and I knew it had a good time in it,” Campbell told Speedcafe.com.
“At the restart, I probably left the pit lane a little earlier (with 9:45s remaining) to ensure we at least got in a base time in case there was another red.
“Thankfully there were no more issues and we produced a time that was good enough.”
Campbell had a solid preparation for this weekend by competing in the German Carrera Cup events at the Austrian track last month where he also clinched a pole and finished with a third place and win in the 31-car field.
“There is no doubt that that weekend was very beneficial,” said the 22-year-old.
“It wasn't just about getting to know the track, but more about more race time and more starts.”
After clinching the pole for his first two Porsche Supercup events before going to finish fifth and third respectively, Campbell came to realise very quickly how important starts are in the highly-recognised and competitive international formula.
Less than a second separated the first 19 cars today.
“I learnt some lessons about starts very quickly in Barcelona,” said Campbell.
“There are a lot of passing opportunities here (Austria), but it would be nicer to get a good start and not have to worry too much about that.
“This track has a high grip level and the Porsche enjoys that.
“We will work on a bit of fine tuning overnight and give ourselves the best chance possible.”