Parupalli Kashyap beat Vietnam's Tien Minh Nguyen in straight sets to enter the knockout stage of the men's singles event in London on Tuesday.
The Indian, ranked 21st in the world, outplayed his rival, ranked 11 places above him, 21-9 21-14 in his final Group D match to finish on top of the group.
While delighted, Kashyap rued that his father could not be there: "My dad didn't get a UK visa in time. I don't know what's going on with the British Embassy."
Kashyap will now take on another giant-killer, Niluka Karunaratne in the Round of 16.
The 48th-ranked Lankan, who has won four international challenge tournaments, surprised eighth seed Kenichi Tago of Japan 21-18 21-16 to top Group C.
Archers on the brink
India's archery challenge is almost over with all archers save Deepika Kumari having crashed out of their respective events. After defeating Korea's JC Evans in a one-arrow shoot-off, Tarun-deep Rai went down 2-6 against world number two Kim Bubmin.
Rahul Banerjee blanked Mongo-lia's Jantsan Gantugs 6-0 in the first round only to lose 3-7 to Poland's Rafael Dobrowlski in the second. Jayanta Talukdar was blanked by American Jacob Wukie in the opening round. In the women's section, Chekrovulo Swuro went down to US's Jennifer Nichols in the shoot-off.
Also read: India's sole judoka out of Olympics | No shame in losing: Bindra | Talukdar, Swuro crash out as archers continue to disappoint | Record of the day | Watchout | Results: day 4 | India at the games | International flavour
(With PTI inputs)