India, June 27 -- Young Indian shuttler Rounak Chouhan packed off world number six and top seed Chou Tien Chen of Chinese Taipei in straight games to create a big upset at the US Open here. World Number 80, Chouhan, who was part of India's bronze medal winning world junior campaign, defeated Chou 21-17 26-24 on Thursday to set up a quarterfinal clash against Misha Zilberman of Israel. The 18-year-old India kept the pressure on his more experienced opponent from the start and though Chou kept his nose ahead till 17-15, Chouhan won six straight points thereafter to pocket the opening game. Chou was the dominant player for most part of the second game as he commanded a 17-11 lead before Chouhan once again bagged six straight points to draw l...