Mandya, Jan 12 : Karan Singh scripted the biggest upset of the tournament when he showed the top seed Kris Van Wyk of South Africa the door to enter the semifinals of the PET ITF Mandya Open. In the first quarterfinal played at the PET Stadium here on Friday, the 20-year-old won in straight sets 6-3, 6-3 to set-up a last-four clash with Jelle Sels of The Netherlands. Sels quelled the challenge of his country mate Thijmen Loof 6-7 (4), 6-1, 6-4 in the longest match of the day that lasted a little over two hours. Following Karan's footsteps was Siddharth Vishwakarma who also registered an upset victory over fifth seed Nam Hoang Ly of Vietnam in straight sets 6-1, 6-4. The lanky Indian will meet third seed Orel Kimhi in the other semifinal. The Isralian stopped the dream run of Madhwin Kamath with a 7-6 (5), 6-0 win. Meanwhile, Karan and his Korean partner Woobin Shin upset the third-seeded pair of Tsung-Hao Huang of Taipei and Kris Van Wyk with a scoreline of 1-6, 6-3, 10-7 to enter the finals of the doubles event. Karan and Woobi will meet the fourth seeded all Indian pair of Parikshit Somani and Manish Sureshkumar who breezed past the top seeded duo of Grigoriy Lomakin of Khazakstan and Austrian David Pichler 6-3, 6-2. The quarterfinal match between Karan and Van Wyk was a see-saw battle as both the players played well and had bad shots, all at the same time. Breaking the top seed's serve in the 1st and third games, Karan, using a strong forehand went 3-0 up. However, the visitor returned the favour, achieving two breaks in the 4th and the 6th game to restore parity. A similar pattern followed during the last three games, where the lad from Haryana broke Van Wyk's serve in the 7th and 9th games to take the first set. The second set saw the players holding on to their respective serves until the seventh game where Karan held a 4-3 edge over his rival. The visitor suddenly lost focus and cool and committed a series of unforced errors to lose his serve in the eighth game, which helped Karan wrap up the match in 53 minutes. In another quarterfinal tie, the 29-year-old Vishwakarma made it look a one-sided affair as the left-hander served with aplomb and returned with fervour. After both the opponents held their respective serves in the first two games, Vishwakarma raced away to grab the first set at 6-1 with breaks in the fourth and the sixth game. The second set saw Hoang claw back in the match going 4-2 up with a break in the sixth game. However, the Indian struck back strongly and didn't give much of a chance to his fancied rival in the next four games, which he won in a row to win the set and the match. /IANS