Mamola finished the race 40 seconds behind the winning Honda of Australian Wayne Gardner and was 10 seconds slower than Eddie Lawson’s second place Yamaha. First British riders home were Rob McElnea (Suzuki) and Ron Haslam (Elf-Honda) in sixth and seventh respectively.
The year’s 250cc GP championship winner Sito Pons (Honda) won the quarter litre class from fellow Spaniard Juan Garriga (Yamaha) while Jorge Martinez (Derbi) took the 125cc race; he was later crowned class World Champion in his first and best season on the world stage.
Dave Thorpe (Honda) won both legs of the British Motocross GP to score a maximum 40 points as he beat the Belgian Eric Geboers (Honda) at Hawkstone Park, Shropshire. Another British rider, Kurt Nicoll (Kawasaki), was fourth.
Elsewhere, The Thierry Sabine Organisation was fined 600,000 French Francs (£58,000) for 12 irregularities in the Paris-Dakar Rally held the winter before. The event claimed the lives of six entrants and a further 30 competitors were seriously injured.