Later in 2000, Duno made her American Le Mans Series debut, she was the first woman to finish in a class podium on this championship. She made her 24 Hours of Daytona debut the next year and her 24 Hours of Le Mans debut a year later. In 2001 and 2003, Duno also competed in the World Series by Nissan open-wheel series in Europe, she became the first woman to score points in this Championship. Also in 2001, she was crowned Vice-Champion Driver in the LMP 675 Class of the American Le Mans Series. She scored an impressive four wins in this class - including the prestigious 10 hours Petit Le Mans – becoming the first woman to score a class win in this major international sportscar competition. In 2004 she scored yet another LMP 675 class win in Petit Le Mans.