Thornton, in his first season of racing with Masters, fought off a challenge from Ian Simmonds (Tyrrell 012) to win the Jerez round on the aggregate of the two parts, having won part one by 12 seconds. In a cat and mouse battle, Simmonds scored his first F1 race win, but as Thornton (Lotus 92/5) stayed glued to his tail throughout the 25-minute race, Simmonds was unable to win on aggregate. Thornton's combined race times gave him the win from Simmonds and with it the Post-1978 Championship title.