Selected as a resting forward-pocket rover, Thornley played in the 1970 VFL Grand Final. He was replaced, at half-time, by eventual match hero Ted Hopkins.[2]
Western Australia 26.18 (174) defeated Victoria (VFA) 5.11 (41), at North Hobart Oval, 9 June 1966, crowd: 20,047 Western Australia 13.11 (89) defeated South Australia 10.14 (74), at North Hobart Oval, 13 June 1966, crowd: 13,969 Western Australia 17.13 (115) defeated Tasmania 16.10 (106), at North Hobart Oval, 16 June 1966, crowd: 10,199 Victoria (VFL) 15.10 (100) defeated Western Australia 13.7 (85), at North Hobart Oval, 18 June 1966, crowd: 23,368