Justin Ruggier has established a healthy lead in the Kumho V8 Touring Car Series after winning a dramatic penultimate round at Wakefield Park.
The Eggleston Motorsport Holden driver backed up his Saturday victory with another commanding performance in Race 2.
Title rival Ryan Simpson won the start and led the early stages but could not hold out Ruggier, who went on to win by three seconds.
The final race provided the biggest talking point however as early leader Ruggier was punted out of the top spot by Simpson at Turn 1 on the second lap.
Ruggier fought back to greet the chequered flag in third and now holds a 44 point lead over Simpson, who finished Race 3 at the back of the eight-car field and received a 10 point penalty for his mistake.
Drew Russell made the most of the drama to clinch his first Kumho V8 race win ahead of fellow Ford driver Matt Chahda.
The results ensured Ruggier, Russell and Chahda made up the round podium; Ruggier's first overall win for the season.
Sydney Motorsport Park's final round offers a maximum of 143 points and promises to be an exciting conclusion to the season.
Other action at the Wakefield Park Shannons Nationals was highlighted by a second 200km Australian Manufacturers' Championship race win for Beric Lynton.
Lynton's BMW 1M pulled away from Garry Holt's Mitsubishi in the early stages, holding a 25 second lead by the time the pitstop cylce was complete.
Holt's co-driver Stuart Kostera charged in the closing stages, but took the flag 12 seconds adrift in second place.
Luke Searle/Barry Graham made it a repeat of Saturday's podium in third ahead of Matt Cherry/Glyn Crimp and Grant Sherrin/Iain Sherrin.
The result was enough to see Lynton pip Grant Sherrin for the title of Australian Production Car Champion.
Brock Giblin, who was badly burnt in an AMC practice crash in July, was on hand at Wakefield to watch the action after recently being released from hospital.
James Golding made the most of a Thomas Randle error in the Formula Fords to take a surprise round victory.
Winner of the weekend's opening two races, Randle collided with Hamish Hardeman in the final, dropping both down the order.
Randle, who was penalised for the incident, came home eighth to salvage second for the round ahead of the consistent Cameron Hill.
In the Super 6 Touring Cars, Gavin Ross secured the title in impressive style, taking a clean sweep of all three race wins.
Adam Proctor meanwhile walked away with the Sports Racer title after an engine failure for Roger I'Anson in Race 2 proved costly for the West pilot.
The final round of the Shannons Nationals will take place at Sydney Motorsport Park on October 31-November 2, featuring the Kumho V8 Touring Cars, Kerrick Sports Sedan Series, Radical Australia Cup, Australian Formula Ford Series and Formula 3 Australian Drivers Championship.