It was their second championship triumph of the season - following a maiden SRC win on the Granite City in April - and more than made up for the disappointment of a non-finish on last month's Jim Clark Reivers.
Faulkner powered his Mitsubishi Evo 6 through the classic Dumfries and Galloway stages to finish 13 seconds ahead of former British Junior Champion Wayne Sisson in an Evo 9, with Stephen Whitford from Ireland third overall in an Evo 6 - both of whom were not eligible for championship points.
Duns driver Euan Thorburn and Campbell Roy were second home of the SRC crews, and also took GpN honours, in their Subaru Impreza.
Jock Armstrong and Kirsty Riddick of Castle Douglas secured the final SRC podium spot in their Impreza N11 and extended their championship lead.
In the drivers' standings, Armstrong now has 131 points, with Faulkner second on 103. There is a similar margin between Riddick and Foy in the co-drivers' championship.
David Bogie of Dumfries remains third in the drivers' table on 101 points, despite crashing out in his Evo 9 on the fourth stage, after "wheel sensor" problems earlier in the day.
Faulkner and Foy set a blistering pace from the start and were fastest through SS1 Kinharvie by two seconds from Willie Bonniwell and Neil Ewing in their Subaru Impreza.
They still had their noses in front after the short Heathhall spectator stage, but only by one second from a hard-charging Bonniwell.
However, on the six-mile Castle O'er stage, the Oban driver picked up a puncture, and Faulkner lost around 20 seconds when he got caught in the dust behind the slower car.
The Evo 6 crew quickly regrouped. They were fastest through stages four and five, but were still only one second ahead of Jimmy Girvan and Mike Ramsay going into the final - and longest test of the day - the 12.75 mile Ae East.
Then disaster struck for the reigning champion when he rolled his Subaru, ensuring Faulkner and Foy a famous victory after notching up their fourth fastest stage time of the event.
Euan Thorburn was well-satisfied with his day's work, which came off the back of a second-place finish on his home event, the Reivers.
The Duns driver was accompanied by Campbell Roy, who took over the co-driver's seat in place of the unavailable Claire Mole.
After the first two stages, the pair were lying eighth overall - just eight seconds separating them from leaders Faulkner and Foy - but they climbed to fifth overall, and third in the points, after posting a second equal fastest time with Armstrong on SS3.
By the end of the fourth stage Thorburn and Roy were third overall, five seconds adrift of new leader Jimmy Girvan.
The pair held station for the two afternoon tests through Ae, and the runners-up spot was their's for the taking after Girvan went off.
"We had a nice clean run for once, after the mis-fires we experienced with the car on the Granite, and early on on the Reivers", said Thorburn, adding: "Every stage seemed to work well - if you'd offered us second in the SRC points and first in GpN at the start of the day, we'd have taken it!"
Eighth overall went to Stonehaven's Barry Groundwater and Jedburgh's Jude Wylie in their Mitsubishi Evo 9.
"It's been very hard going - we seemed to go to sleep a bit on the opening stage, and they stages have been very loose and slippy, particularly the final run through Ae which was like the driveway up to a stately home, but it's been enjoyable all the same."
Steve Bannister and Louise Sutherland from Hawick were again the crew to beat in the two-wheel drives, the pair rounding off the top ten in their Escort Mk2.
In 16th place overall were Craig McMiken (Newton Stewart) and Christine Sanderson (Berwick) in their Mitsubishi Evo 9 while 26th overall and third in their class were the Duns crew of Mike Horne and Robbie Mitchell in their Mk21 Ford Escort.
Winning his class yet again in the Historic event was Duns driver Walter Aitken in his Mk 1 Ford Escort. Non finishers included Duns driver Garry Pearson who broke a driveshaft on his Peugeot 205 GTi.