Garth Tander and Tony Quinn emerged victorious from a thrilling first running of the Australian GT Championship's Phillip Island 101 at the Shannons Nationals.
The three-time Bathurst winner had clawed back some 20 seconds to Le Brocq over the final 34 lap stint.
The race was eventually called after 82 of its scheduled 101 laps due to time constraints.
Tander had also taken the John Bowe-driven Ferrari during his charge, with the Italian entry eventually rounding out the podium in third.
“I didn't know what the margin was to the leader,” said Tander of his charge.
“They just told me that I had to catch the Ferrari and then once I got past JB they told me I was 15 seconds behind the Mercedes. I started taking big chunks out of it.
“The car was beautiful and we were doing as fast a lap at the end of the stint as we were at the beginning.
“I hadn't driven the car at all in the dry before jumping in today and I was learning on the run.
“About half way through I learned a few things that worked and found a fair bit of time.”
The result came on Tander's debut in the Australian GT Championship.
“It's been about 11 years since I've driven anything that wasn't a V8 Supercar and it was my first time in a GT3 car – and I loved every minute of it,” he said.
“I can't thank Tony enough for giving me a shot and I hope he asks me back!”
Saturday at the Shannons Nationals also saw qualifying for the Australian Manufacturers Championship and the opening race for the Radical Australia Cup competitiors.
The BMW 135i of Grant and Iain Sherrin will start the AMC's Great Southern 4 Hour from pole after drying conditions during the second of two quailing sessions helped shake-up the pecking order.
The Sherrin BMW was almost a second quicker than its nearest rival, fellow Class B runners Peter O'Donnel and John Bowe in the former's BMW 335i.
Bob Pearson/Glenn Seton held up the Mitsubishi flag in third while Glenn Crimp/Matt Cherry and Beric Lynton/Tim Leahey made it four BMWs in the top five with their 1Ms.
The opening 40 minute Radical heat was meanwhile slashed to less than half its intended duration after a fracas on the warm-up lap took out four cars and delayed the start.
Peter White claimed victory after early leaders and eventual second and third place finishesTim Berryman and Neale Muston proved unable to recover from their longer pitstops.
A second 40 minute Radical encounter will be held tomorrow, sharing the billing with the Great Southern 4 Hour and second heat for the Carrera Cup Pro-Am.
CLICK HERE for Speedcafe.com's separate report on today's Carrera Cup action