DYLAN O'KEEFFE has topped the fastest ever Friday for the Porsche Paynter Dixon Carrera Cup Australia Championship at Hidden Valley Raceway, heading a tightly-packed field across a pair of practice sessions at the Darwin circuit.

Adrian Flack edged out Tim Miles to top the Morris Pro-Am class battle, with 24 of the 29 cars entered covered by just 1.5 seconds across 50 minutes of running today.

O'Keeffe charged to the top late in practice two, as teams fitted new Michelin tyres for a qualifying simulation late in the second of two practice sessions on the program.

His 1m06.5518s scythed seven-tenths from the existing practice / qualifying record at Hidden Valley with times likely to drop further during qualifying in cooler conditions on Saturday morning.

O'Keeffe's Dexion / RAM Motorsport entry headed practice one pacesetter Harri Jones by just 0.13 seconds.

Jones had earlier topped the first session and backed up his early pace with a strong run in the second session later in the day.

David Russell was third in his EMA Motorsport en, continuing that team's strong form from Winton Motor Raceway last month - where he was a podium finisher.

Christian Pancione was fourth while fellow Michelin Junior Callum Hedge was fifth for Team Porsche NZ / EBM.

David Wall - who will notch up his 200th career race start on Sunday afternoon - was sixth while Luke Youlden, Dale Wood, Michael Almond and Ryan Suhle completed the top-10.

Ultimately, eight drivers lapped beneath the existing Qualifying record at Hidden Valley with more lap time likely to be found in qualifying tomorrow.

Adrian Flack topped the Morris Pro-Am field, but that group was as tightly packed as the Professional class runners.

His 1m07.7957s best was just 0.08s quicker than Tim Miles, while Sam Shahin was a further 0.004s further back in third.

Flack topped both Pro-Am sessions on Friday having paced the earlier 25-minute opening session in the morning.

Liam Talbot was fractionally behind the leading trio with Rodney Jane, Stephen Grove and Geoff Emery all within 0.5 seconds of Flack's session best.

Round 2 Pro-Am winner Matt Belford was next, with Dean Cook, Marc Cini and Scott Taylor rounding out the Pro-Am runners.

The lone 20-minute qualifying session to decide the TAG Heuer Pole Award winners will commence at 10:10am local time on Saturday, with the first race of the weekend - over 18 laps - to commence at 2:10pm in the afternoon.

Both sessions will be shown live on Fox Sports 506 and Kayo Sports, with the race also shown live on the Seven Network.

Dylan O'Keeffe - Pro

"It was a pretty good day. I always like coming here and felt comfortable in the first session straight away. We were fairly quick, top five, in the first session and didn't change too much for practice two. You just have to put a lap together, you've got to back right off and get a gap and then you only need a minute to set a lap. I made it work in the last one.

With these Michelins it's the complete opposite to Winton, where you last lap was the fastest. This time it will be your first lap, which is different to what I'm used to on these tyres. My fastest lap would have been on lap one on my new set of tyres and that was to make sure we were up front for the qualifying session tomorrow - it's about using your experience from the past and being smart about it. The car was really good."

Adrian Flack - MORRIS Pro-Am

"I just love coming to Darwin! It's such a good track, the people are great and it's a really good event and I'm looking forward to coming out tomorrow and having a go. I felt good. I was just playing around with a few of the Pro's and they weren't pulling away on me which was good, so we're up there. Qualifying will be head down and go for it, and see what happens at the other end."