Moreno became a senior gymnast in 2003. Moreno competed at the 2003 World Championships in Anaheim, California. Here she and the Spanish team placed 5th in the team final, therefore qualifying a full team to the 2004 Olympics. Individually, she placed 22nd in the all around competition. In 2004, Moreno was named to the 2004 Olympic team, where the team placed 5th. Individually, Moreno won Spanish women's artistic gymnastics' first ever Olympic medal in Athens, where she was third on floor with score of 9.487. During the Olympics, Moreno also debuted a 3 and a 1/2 twist on floor, a move which is now named after her. Moreno has also trained a quadruple twist, though it was never performed internationally.