Two-time World Championships bronze medalist, PV Sindhu will lock horns with reigning champion Carolina Marin of Spain in the semi-final of the Denmark Open Badminton tournament at Odense today. Sindhu, who is unseeded in this tournament, had defeated sixth seed and former world number one China's Wang Yihan in straight games, 21-18, 21-19 in the quarter-finals yesterday to make it to the semi-final. She is the lone Indian left in the tournament. World number one Saina Nehwal and Kidambi Srikanth had made exits in the per-quarterfinals.