In January 1977, Reid won her only Grand Slam singles title when she defeated fellow Australian Dianne Fromholtz 7–5, 6–2 in the final of the Australian Open. Reid and Fromholtz were the only top 10 players who played the tournament. The previous week, Reid also defeated Fromholtz in the final of the New South Wales Open, where Reid and Fromholtz again were the only top 10 players who entered. On both the Virginia Slims and the Colgate Grand Prix tours in 1977, Reid qualified for the season-ending tournaments (each limited to the top eight players on the respective tour). In World Team Tennis, Reid was undefeated in singles against both Martina Navratilova and Virginia Wade, defeating each three times.