Stevenson started her career by becoming Junior World Champion in 1998. In 2000, she won the 3rd place in taekwondo at the 2000 Summer Olympics's World Qualification Tournament and qualified for the 2000 Summer Olympics in Women's 67 kg. These achievements won her fame and drew the attention of martial arts superstar Jackie Chan[3] who sponsored her while promoting his film Shanghai Noon in the United Kingdom. But in the 2000 Olympics she lost to Norway's Trude Gundersen in the semifinal and Japan's Yoriko Okamoto in the bronze match. The next year, she became a world champion in the 2001 World Taekwondo Championships's Women's Middleweight, defeating 2000 Summer Olympics gold medalist Chen Zhong in the final. She became the first British Taekwondo World champion.
2008 Olympics
Due to an "error" in judging, Stevenson almost exited the 2008 Olympics in the quarterfinal stage following her match with China's Chen Zhong, the gold medal favourite. In the final round of the match, the judges failed to award Stevenson two points for a high-kick to the head, which would have put her one point in the lead with 10 seconds remaining. Following the match, the British team representative immediately made an official protest and, after studying video footage of the kick the judges reversed the result of the fight and Stevenson progressed to the semifinal. Stevensons's semifinal opponent was María del Rosario Espinoza of Mexico, and she lost 4–1, also sustaining a twisted ankle. She then went on to compete for bronze in the repechage, defeating Noha Abd Rabo of Egypt and winning Britain's first Olympic medal in the sport of taekwondo.[4]
On announcing the change of result in the quarter final, the tournament director said:
"The competition supervisory board has looked into this matter deeply, has made video analysis which has been open to all the referees and judges. In applying paragraph two of page 64 of the competition rules of the World Taekwondo Federation we have to change this result and we have to declare the British player as winner. We are very sorry to the spectators of China but justice is first. Thank you for understanding."
As a result of this judging error in particular, emphasis may be switching to having electronic scoring equipment contained within the actual body protectors themselves, and many tournaments are now using these in trial phase. However, since this technology is far from refined, and due to tactical differences needed in gameplay and style, Stevenson, and athletes from other National Teams, currently do not favour this system and often boycott such tournaments.