In 1964, at 18 years, Stahl won the Romanian national championship with Unio, and transferred to CSA Steaua in Bucharest. The same year, she took part in her first Olympics in the team foil event. Romania was defeated by the Soviet Union in quarter-finals and finished 5th after prevailing over France. In 1965 she won the Junior World Championships in Rotterdam. She also earned a team silver medal with Romania at the senior 1965 World Fencing Championships. She earned her first major individual medal, a bronze, at the 1966 World Fencing Championships. She would earn two individual medals, including gold in 1975, and seven team medals at the World Championships throughout her career.