Mrs. Hy-Boulais was born in Cambodia and moved to Hong Kong when she was 6 years old. Seemingly diminutive in physical stature, her game was anything but. At the young age of 14, she won the ITF Hong Kong Open Junior Championships in 1979 and repeated the feat in 1981. Mrs. Hy-Boulais made history in 1983 when she reached the final of the prestigious Junior Wimbledon Championships in girls singles, and won the girls doubles there, reaching a career high of no.7 in the ITF doubles rankings. These results are still the benchmark of subsequent generations of junior players today.
From 1981-87, she played a total of 14 Fed Cup ties for Hong Kong. She is best remembered for her 3 set
battle against then world No.2 Steffi Graf in the World Group Competition in 1987, before Germany went on to win the Fed Cup. That year, she led Hong Kong to victories against Finland, Belgium, Brazil and Sweden before losing to the Netherlands in the World Group consolation final. She was an NCAA Division 1 singles All-American at UCLA in 1984. Mrs. Hy-Boulais turned professional in 1986, and in the same year, she won her first and only WTA title of her career in Chinese Taipei, reaching no.65 in the WTA singles rankings.
In local tennis competitions, Mrs. Hy-Boulais dominated all tournaments. She won the Hong Kong National Tennis Championships, CRC Open and SCAA Open women’s singles and doubles in 1978. She successfully defended her singles and doubles title at CRC Open and SCAA Open in 1979.