The venture with Ford was not without success. Brock won his first ATCC race since the 1986 when he stormed to victory in the final round of the 1989 ATCC at Oran Park to claim 3rd in the championship behind the Shell Sierra's of Dick Johnson and John Bowe. Brock went on to claim his last Bathurst pole position at the 1989 Tooheys 1000, but a rear hub failure caused the No. 05 car's retirement on lap 81 while the team's second Sierra (#105) driven by Brad Jones and Paul Radisich finished in 9th place. At the end of the year, Brock and Radisich drove the Sierra to victory in the Nissan-Mobil 500 Series in New Zealand. Brock also claimed pole position for the Group A support races at the 1989 Australian Grand Prix in Adelaide, though he only managed to finish 2nd and 5th in the two races after a couple of spins caused by his Bridgestone tyres not handling the hot conditions during the Saturday race, or the very wet conditions on the Sunday.