The 20-year-old Nagal, who was returing to tournament play after an injury lay-off, appeared a bit rusty and his 32-year-old rival Ranjeet took full advantage to take the first set with a break in the 8th game.
Ranjeet played a steady game and capitalised on Nagal's uncharacteristic mistakes. He broke the top-seed's serve early in the second set to lead 2-1. At this point Sumit found his rhythm and range. He began to strike the ball powerfully and won 11 of the last 12 games to wrap the second set 6-3 and the third 6-0 to reach the second round.
In another upset, Korean Seong Gooh Oh outplayed sixth seeded Yurii Dzhakvakian of Ukraine, conceding only one game.
There were wins for No.3 seed Colin van Veen of the Netherlands and seventh-seed Cameron Silverman of USA.
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Results (Indians if unless otherwise specified): Singles: Cameron Silverman (US) bt Jessy Kalamby (SUI) 6-3, 6-2; Arjun Kadhe bt Lucas Gomez (MEX) (4) 6-2, 6-3; Ju-Hae Moon (Korea) bt Dhruv Sunish 7-5, 6-2; Kelsey Stevenson (Canada) bt Vladimir Polyakov (Russia) 6-3, 4-6, 6-4; Tae-Woo Lee (Kor) (8) bt Kunal Vazirani 6-3, 6-0.
Doubles: Yurii Dzhavakian/Jessy Kalambay bt Fahad Mohammed/Rishabdev Raman 7-6(6), 4-3 Retd; Tae-Woo Lee/Ju-Hae Moon bt Lucas Gomez/Kazuma Kawachi (Japan) (4) 6-3, 6-3; Mohit Mayur Jayaprakash/Vinayak Sharma Kaza (2) bt Cing-Yang Meng/Li-Wie Tan (Taipei) 6-1, 7-6(2); Vladimir Polyakov/Colin van Beem (1) bt Paramveer Singh Bajwa/Anurag Ne 6-4, 6-4.
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