On June 11, 1978, the NAPA 400 was held at Riverside International Raceway as the 14th race of the 30-race 1978 NASCAR Winston Cup Series season, with a 35-car field contesting 95 laps on the 2.62-mile road course.
David Pearson captured the pole in the #21 Purolator Mercury for the Wood Brothers with a speed of 112.882 mph. Benny Parsons, starting fourth in the #72 1st National City Travelers Checks Chevrolet for L.G. DeWitt, scored the victory by 29 seconds over Richard Petty. Bobby Allison finished third, followed by Dave Marcis and Cale Yarborough. Parsons collected $22,750 for the win—his third of the season—and led 26 laps. He averaged 104.311 mph in a race slowed by only one caution for four laps.












