Paul Dumbrell has shattered the practice record in the opening session for this weekend’s Rabble.Club Sandown 500.

In the first of two co-driver sessions for the day, Dumbrell broke the record which Jamie Whincup set in qualifying four years ago by 0.7263s in Whincup’s own #1 Red Bull HRT ZB Commodore.

Dean Fiore (#23 Drive Nissan Altima) finished the 30-minute session 0.4319s slower in second position, ahead of Jack Perkins (#25 Boost Mobile ZB Commodore), Alex Rullo (#78 Harvey Norman Nissan Altima), and Jonathon Webb (#19 Tekno Autosports ZB Commodore).

Shell V-Power Racing’s Alexandre Premat (#17 FGX Falcon) and Tony D’Alberto (#12 FGX Falcon) were the only two Fords in the top 10 in seventh and ninth respectively.

Dumbrell, who also topped Super2 Practice 1 in record pace earlier in the morning, had already undercut Whincup’s mark on his first run before lowering his best time to 1:07.8467s just prior to the halfway mark.

“The track’s quite good,” said the 2012 Supercheap Auto Bathurst 1000 winner.

“The surface looks like it’s deteriorated since it’s been resurfaced in Turn 1 and 4 and whatnot, but the lap times say something different.”

Regarding the work to fill in cracks in the track surface, Dumbrell predicted, “It will be good today, but it will be diabolical tomorrow. Bit of wet weather on that type of stuff never makes it nice.

“But I think as the track gets a bit warmer today it will come into its own and I think this afternoon it will be pretty impressive.”

Webb was the next under the old record in the final four minutes before Rullo, in Simona de Silvestro’s car, and then Fiore, in Michael Caruso’s, slotted into second position.

“We had the full test day in Car 78, got to do a lot of laps last week,” explained Rullo.

“(It was) Good to jump straight into the (Super2) car, feeling pretty good and obviously we’re on softs as well, which makes it pretty easy.

“I was able to jump straight into this car (de Silvestro’s) and be on pace.”

The two Altimas were split in the final minute by Perkins in the James Courtney entry, while Scott Pye’s #2 Walkinshaw Andretti United ZB Commodore was ultimately sixth-fastest in the hands of Warren Luff.

Premat was 0.7386s off Dumbrell’s pace in Scott McLaughlin’s Ford, while Garry Jacobson took Rick Kelly’s #15 Castrol Nissan Altima to eighth and Steven Richards rounded out the top 10 in Craig Lowndes’ #888 Autobarn ZB Commodore.

The first of the Tickford Racing cars was Chaz Mostert’s #55 Supercheap Auto FGX Falcon, driven by James Moffat to 13th position.

One spot further back was Earl Bamber in championship leader Shane van Gisbergen’s #97 Triple Eight ZB Commodore.

The top 16, rounded out by Will Brown in Anton De Pasquale’s #99 Erebus ZB Commodore, were within a second.

Dean Canto’s relatively harmless spin at Dandenong Road was the main incident during the session.

He ended up second-slowest in the Mark Winterbottom #5 Bottle-O FGX Falcon, ahead of Matt Stone Racing rookie Bryce Fullwood (#35 Bigmate VF Commodore).

Practice 2, a half-hour hit-out open to all drivers, is scheduled for 1230 local time/AEST.

Results: Supercars Practice 1 (Co Drivers)