Two-time champion Saina Nehwal scored a hard-fought victory, but it was Parupalli Kashyap who created a flutter by stunning top seed Chen Long of China in straight games to make the last eight in the Indonesia Super Series in Jakarta on Thursday.
The world No 26, Kashyap, who qualified for the London Olympics at the last moment during the India Open Super Series in New Delhi, defeated Chen, ranked third, 21-17, 21-14 in 45 minutes in the men's singles.
He will next take on Hans-Kristian Vittinghus of Denmark on Friday.
Earlier, fifth seeded Saina survived a scare from world No 46 Aprilla Yuswandari of Indonesia before winning 21-17, 14-21, 21-13 in a women's singles match that lasted almost an hour.
The world No 5 Indian, who was runner-up in the last edition of the tournament, will meet third seed Chinese Shixian Wang, who got the better of Juan GU of Indonesia 21-12, 21-11 in another match.
Saina, who won the title in 2009 and 2010, holds a 2-1 record against Shixian and had beaten the Chinese in the final of the Swiss Open Grand Prix Gold in March for her first title this season.
Kashyap rode on his smashes and better net play to outwit the Chinese.
The Indian had pocketed 26 smash winners and accumulated 14 points from the net. Chen, in comparison, had 21 smash winners and only seven at the net.
In the first game, after conceding a narrow 1-4 lead, Kashyap clawed leveled at 8-8 and kept his nose ahead to pocket the game.
Chen, who had a 3-1 record against Kashyap before Thursday's match, again opened up a narrow 4-2 lead in the second game, but the Indian fought back to catch up at 9-9 and then took giant steps to seal the issue.
Earlier in the day, Saina kept her campaign on track but was fully tested by the local girl.
The Indonesian opened up a 3-0 lead but was locked in a keen contest till 14-14 before Saina registered five straight points to march ahead and take the first game.
Not ready to take it lying low, Aprilla was on the offensive from the start of the second game. She surged ahead from 10-10 and took the game at 21-14.
In the decider, Saina played more smashes and accumulated points from the net. Aprilla lagged behind right from the start and soon ran out of steam as the Indian sealed the issue comfortably in the end.
Saina had won the Thailand Open Grand Prix Gold last week in Bangkok.
In the men's singles, Ajay Jayaram suffered a 15-21, 14-21 loss to Indonesian Dionysius Hayom Rumbaka in 35 minutes and crashed out of the tournament.
In another match, eight seed German Juliane Schenk ended P V Sindhu's run in the tournament, beating her 21-14, 21-14 in 33 minutes.
