The 20-year-old pulled off a stunning outside pass on Broc Feeney at the high-speed Turn 1 to take the lead of the race.
It occurred immediately after a Safety Car restart as rain fell while all the front-runners were on slick tyres.
The sophomore Supercars driver said similar conditions at the end of last year’s Sunday Sydney race gave him the confidence to attempt the move.
“I had a great restart and put a lot of pressure on Broc. I had a good run on him and I knew he was going to block the inside,” Allen told the broadcast of the moment.
“Because it was drizzling, I knew the race line at Turn 1 was going to be very slippery because of last year when it rained in this same scenario, so I just tightened the seatbelts.
“I was pretty comfortable. I knew I had it when I had a good run on him, bombed it into Turn 1 and judged the gap, got on the grippy stuff right around the outside of him.
“It’s a credit to him; he could’ve been an absolute dog and just pushed me straight off the track, but Broc being Broc, we had good hard racing and put on a good spectacle for the fans.”
Unfortunately for Allen, he handed the lead back to Feeney when he ran wide at Turn 8 on the same lap – a mistake he said he will “never forget until the day I die”.
It was not to be anyway, as the #26 Penrite Mustang suffered a steering failure while sitting second to Feeney eight laps from the finish.
The team put the failure down to side-to-side contact between the two warring Ford drivers on the first lap of the race, where Feeney held out his fellow front-row starter.
Race winner Feeney later praised Allen’s “ballsy move”, as well as the general nature of the racing in the category.
“I don’t know if there’s a better racing category in the world right now in terms of door-to-door, hard racing,” he said.
“You see a lot of F1 drivers complaining that they can’t pass… and then you’ve got us, a couple of young kids going side-by-side on slicks in the wet at Turn 1.
“That was a ballsy move from him and he pulled it off. We had a lot of fun, we were banging doors for a while there.
“I’d make a mistake, he got me, then he made a mistake and I got him back, and then he will all over me before he had the issue.”
Allen sits 13th in the standings after round one, while his teammate Matt Payne is equal with Feeney at the top of the order.
Grove Racing is second in the teams’ championship, sandwiched between fellow Ford squads Tickford Racing and Triple Eight.
This article first appeared on Speedcafe.com, a sister site to MotorRacing.com.