47th in world rankings before the event, she reached the final of the 2003 World Fencing Championships in Havana after defeating Cuba's Ana Faez Miclin in the quarter-finals, then Italy's Gioia Marzocca. She met reigning world champion Tan Xue of China and defeated her by a single hit to win the world title. By circumstance Mihai had found herself at the championships without her fencing mask and had been forced to use a Lexan visor mask, promoted by the International Fencing Federation because it shows the fencer's face. By winning the competition, Mihai also received a prize of $10.000 offered by the federation to the best-ranked athlete wearing a Lexan mask. For her performance Mihai was named "athlete of the year" along with weightlifter Valeriu Calancea.