Tesch started playing wheelchair basketball after one of her physiotherapists noticed how skilled she was at shooting with a foam basketball and perspex backboard during her rehabilitation. Shortly after entering the New South Wales state team, she was invited to try out for and made the Australia women's national wheelchair basketball team in 1990, making her national debut at that year's World Championships and her Paralympic debut at the 1992 Barcelona Games. She was named to the All Star Five at the 1994 Gold Cup, where the Australian team won a bronze medal. She was part of the Australian team at the 1996 Atlanta Paralympics, and was named Most Valuable Player at the 1998 Gold Cup. She was the vice-captain of her country's team at the 2000 Sydney Paralympics, where she won a silver medal. During celebrations after the games, some players from Europe invited her to play in professional men's teams there. She accepted this suggestion, and played in Madrid, Sardinia, and Paris for the next five years, thus becoming the first woman in the world to play wheelchair basketball professionally. She helped establish a women's wheelchair basketball league on the continent and competed in women's teams in Italy and France. She also competed in the silver-medal-winning Australian team at the 2004 Athens Paralympics. She returned home to captain the national squad at the 2008 Beijing Paralympics. In 2010, Tesch competed with her team in the Osaka Cup, a competition for the top five women's international wheelchair basketball teams in the world; her team defeated the number one ranked American team 55–37. She was a 4-point player. She retired from the national wheelchair basketball squad in 2011 to concentrate on sailing.