The Keralite was in fantastic form in the opening round as he knocked out World No. 9 NG Ka Long Angus 13-21, 21-18, 21-19 in a thrilling match that lasted an hour and 11 minutes. The 29-year-old didn't get a chance to practice in the main hall ahead of his match but didn't let that affect him.
Prannoy dug deep to showcase his giant-killing qualities in a match that had fans on the edge of their seats. This was his second big upset in three tournaments, having accounted for reigning Olympic champion Viktor Axelsen at the Indonesian Masters last month.
Up next for the the former World No. 8 is veteran Malaysian campaigner Daren Liew, ranked 36th in the world. Prannoy last got the better of him in the first round of the Indonesia Masters and will aim for a repeat to make the most of a depleted draw at the BWF World Championships 2021.
While Prannoy is the only singles star from the Indian contingent in action on Day 4 of this prestigious tournament, there will be a couple of doubles pairs looking to cause upsets.
World No. 21 women's doubles duo Ashwini Ponnappa and Sikki Reddy meet the 14th seeds Liu Xuan Xuan and Xia Yu Ting of China. Xuan and Ting were quarterfinalists at this year's Denmark Open.
The young Indian men's doubles combine of MR Arjun and Dhruv Kapila, meanwhile, will face 11th seeds and reigning European champions Vladimir Ivanov and Ivan Sozonov.
BWF World Championships 2021: Full schedule for Indian shuttlers on Day 4
HS Prannoy (IND) vs Daren Liew (MAS) at 9 am local time/1.30 pm IST.
MR Arjun/Dhruv Kapila (IND) vs (11) Vladimir Ivanov/Ivan Sozonov (RUS) at approx 9.40 am local time/2.20 pm IST.
Ashwini Ponnappa/Sikki Reddy (IND) vs (14) Liu Xuan Xuan/Xia Yu Ting (CHN) at approx 9.40 am local time/2.20 pm IST.
BWF World Championships 2021: TV schedule
The BWF World Championships 2021 will be telecast live on the Star Sports 3 and Star Sports 2 HD TV channels in India.
BWF World Championships 2021: Live streaming details
The BWF World Championships 2021 can be live-streamed on the Disney+Hotstar app.