The 1973 Winston Western 500 was a Winston Cup Series (now Sprint Cup) event held at Riverside International Raceway on January 21, 1973. It was the season opener for both series. Mark Donohue won his only career race in solid fashion, leading 138 of the 191 laps in route to a one-lap victory on Bobby Allison. Eventual 1973 champ Benny Parsons finished 14th to begin the year. Stats