By achieving the feat, the 19-year-old fell in line to become the first Indian to win two medals at the sport's most prestigious event -- having won the bronze last year at Guangzhou.
The 11th seeded Hyderabadi proved that she belongs right at the top of the sport by defeating Chinese World No.2 Shixian Wang 19-21, 21-19, 21-15 in a marathon match which lasted an hour and 25 minutes at the 9,200-seater stadium. This is World No.12 Sindhu's fourth victory over second seeded Shixian in six meetings.
Meanwhile, seventh seed Saina had to once again suffer a quarter-final defeat at the world meet when she lost 15-21, 15-21 in 45 minutes to Chinese World No.1 and top seed Li Xuerui. The last-eight match seems to be a jinx for the World No.7 Saina, who has now lost five matches on the trot at the Worlds since 2009.
Sindhu got off to a brilliant start, racing away to 11-4 at the first game break. The tall and lanky Indian further extended her lead to 15-11 making optimum use of her height.
But slowly Shixian found her rhythm and with brilliant court coverage closed the gap and went into the lead. After letting the game slip through, the Indian tried fighting back but the former World No.1 sealed the game on her second gamepoint.
Sindhu turned the tables in the second game by going into a 5-1 lead but with the help of some amazing deceptive shots and cross-court slices the World No.2 once again took the lead (16-12).
Like in the third round match Thursday, Sindhu found her legs and bagged the next eight consecutive points to reach gamepoint (20-16). The Chinese girl saved three but Sindhu was able to push the match into the decider on her fourth gamepoint.
It was the closest of affairs in the final game where service was exchanged after almost every point. But full credit to Sindhu who extended the rallies at the start to tire out the reigning Asian Games champion. And from 15-all, the Indian notched the next six points to seal the tie in her favour.
This is only the fourth time that an Indian was in line for a medal at the Worlds. Legendary Prakash Padukone started the trend here in 1983 when he won the men's singles bronze. It took Indian shuttlers another 28 years to win a metal when Jwala Gutta and Ashwini Ponnappa clinched the women's doubles bronze in 2011.
Then Sindhu won the women's singles bronze last year and now was in line for a back-to-back medal.
The Hyderabadi teenager has a great chance of improving on the colour of the medal when she takes on the winner of the match between Chinese Taipei's eighth seed Tzu Ying Tai and Spanish ninth seed Carolina Marin in the semi-finals Saturday.
However, earlier in the day, reigning Olympic champion Xuerui gave a tough time to Saina in the first game, leading from the start till the game finished in her favour. The World No.1 looked in her prime as her shots were exquisitely dropped or smashed, beyond the reach of Saina.
Out of nowhere, Xuerui would come out with immaculate shots which would catch the Indian completely off-guard.
After regularly exchanging services at the start of the second game, the seventh seeded looked like she would push the match into the third game when she had a lead of 12-8.
However, the top seed extended the rallies which tired out Saina leading to Xuerui win 13 of the next 16 points and enter the semi-finals.