Virtually all the Castrol Championship contenders lined up on slick tyres as their race began in the dry. Stuart Graham, now sponsored by Brut 33, had only done three laps in the dry Saturday afternoon session before an earth lead broke and his Camaro's battery cut out, so he was only on the middle of the front row sandwiched between Vince Woodman and Richard Lloyd. Both their Camaro's had had trouble in practice with front Dunlops going oval and causing considerable front-end vibration. However the problem was traced to a faulty batch of tyres and they were re-equipped in time for the race. Lloyd's car was the one he wrote off at Brands in March which had been put back together again to replace the Camaro damaged at Ingliston.
When the race started Graham made no mistake about getting away first, and although Lloyd was able to hold onto him for a while, everyone else was soon left well behind. Woodman completed the first lap in third place ahead of Jon Fletcher's Camaro and Tony Lanfranchi's BMW, which was being chased hard by its 4-litre class compatriots, Tom Walkinshaw (3.0 Ford Capri) and Peter Hanson (2.8 Opel Commodore). After being joint fastest in his class with Tony Dron in practice, Andy House's race got off to a very bad start when his Dolomite's throttle cable jumped off on the first lap and by the time he'd replaced it he was a lap behind. Consequently, Barrie Williams came round heading the 2500 cc class in tenth place overall after the first lap, his Mazda being chased by the Dolomite Sprints of John Handley and John Hine. In the smallest class, Stan Clark's Alfa made an excellent start to put three cars between himself and nearest rival Bernard Unett (1.6 Hillman Avenger) on the first lap, while John Markey was right behind Unett in the Toyota Celica. Out in front, Graham continued to extend his lead and the interest shifted to Woodman, who was definitely catching Lloyd for second place. However, Woodman's clutch was overheating and he was having trouble getting gears which, when added to the heavy rain that began to fall after about six laps, added up enough to make him spin at Lodge on the ninth lap, which let Lloyd out of his grasp for the rest of the race. With Graham, Lloyd and Woodman taking the first three places overall, fourth place eventually went to Walkinshaw after an exciting tussle with Lanfranchi. While it was still dry, Walkinshaw fought his way past the BMW, but when the rain really set in Lanfranchi came back at him and regained the class lead. He stayed there for a few laps, but once the rain slackened off the heavy BMW was again at a disadvantage and Walkinshaw went through to win the class. Lanfranchi finished fifth overall despite a slipping clutch and a last lap challenge from Hanson who reeled him in rapidly after disposing of Fletcher's floundering Camaro and crossed the line in a dead heat for second in class.
Behind Fletcher in eighth place, Williams took a convincing 18.5 second class win and a new lap record after an excellent drive that gave the Dolomites their hardest defeat yet. Handley just beat Dron for second in the class, while Hine dropped back to fourth after going wide at Deer Leap and losing time getting unstuck from the mud. Nevertheless his performance was extremely creditable, or perhaps even incredible, to those who'd seen the car after he'd demolished the back end against the Old Hall armco in practice and didn't expect him even to start the race. Chris Craft's Dolomite had been overheating in practice and he'd only done three laps of the race before the problem set in again and he retired to the pits.
In the 1600 cc class, Markey set a new lap record as he worked the Toyota to the front, but then the rain caught him out at Old Hall and he spun down behind Unett and Clark. The Alfa and the Avenger spent the closing laps of the race locked in combat, with Unett just getting the class win as they crossed the line side by side.