Prannoy, who sent the top seed and world No 2 Jan Jorgensen of Denmark packing out of the tournament, conjured up hopes of another upset before losing to world No. 6 Viktor Axelsen 21-16, 9-21, 18-21 in 58 minutes.
Commonwealth Games bronze medallist Guru, despite playing a compact game initially, ran out of ideas and went down 21-15, 18-21, 13-21 to China's Xue Song.
"I was making lot of mistakes on the sideways, smashes were not accurate and I was not patient on the court. I am not happy with my performance today," Prannoy said.
Sugiarto stuns crowd favourite Lin Dan
Meanwhile, Indonesia's Tommy Sugiarto earned the prized scalp of five-time World champion Lin Dan, beating the Chinese legend to reach the men’s singles semi-finals.
Former world No 3 Sugiarto scraped past the two-time Olympic champion 21-17, 15-21, 21-17 in a gruelling contest to silence the vociferous crowd, which chanted 'Lin Dan' 'Lin Dan' right through the match.
"You know who Lin Dan is. He is a legend in badminton. I had lost to him thrice so I had to come up with my best as I know Lin Dan's game," Sugiarto said, still feeling out of breath after battling for an hour and 18 minutes.
"He is a superstar wherever he goes. The crowd was backing him so I had to motivate myself and concentrate point after point. I am happy, this is one of my best wins," he added.
Talking about Lin Dan's game, Sugiarto said: "I think he has changed his game in the last few years. His game was more of speed power but he has more accuracy. For me I had to match his accuracy.
"I think at 15-all, Lin Dan lost his concentration. He made a lot of mistakes."
Asked what is the most difficult thing facing Lin Dan, he said: "He is extremely confident. So I had to come up with my best game.
"He is a special player. Sometimes he is at his best and sometimes he doesn't give his best."
Image: Saina Nehwal
Photograph: Getty Images
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