Fullerton (US), June 26 : Indiaâ??s Rounak Chouhan created the biggest upset of the US Open badminton tournament here on Thursday when he packed off World no 6 and menâ??s singles top seed Chou Tien Chen of Chinese Taipei in straight games.

World No. 80, Chouhan, who was part of Indiaâ??s bronze medal winning world junior campaign, defeated Chou 21-17, 26-24 to set up a last eight 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 level. It was a neck-and-neck battle thereafter as Chouhan saved four game points before converting his second mach point to clinch victory in 49 minutes.

Earlier, in the qualifiers, Rounak Chouhan booked his place in the main draw with two convincing wins, first getting the better of France's Enogat Roy 21-19, 21-16 before recovering from a set down to beat Chinese Taipei's Kuo Kuan Lin 13-21, 21-14, 21-10. The rising Indian shuttler then rode on that momentum to win the first of the two all-Indian contests, beating former World Junior Championships silver medallist S Sankar Muthusamy 23-21, 21-16 to enter the second round.

Also advancing to the last eight stage were world junior silver medallist Tanvi Sharma, Rakshitha Sree and Devika Sihag in womenâ??s singles.

Fifth seed Tanvi defeated Tung Ciou-Tong of Chinese Taipei 21-12, 21-19, Rakshitha got the better of Tungâ??s compatriot Chen Su Yu 21-4, 21-19 while sixth seed Devika beat Tonrug Saeheng of Thailand 21-17, 21-19.

The experienced Kidambi Srikanth then capped off a fruitful day for India with a 21-14, 21-13 win over Lee Zii Jia of Malaysia.

/IANS