HS Prannoy's campaign ended in disappointment as he retired hurt due to an injury, while Ayush Shetty also bowed out as India's challenge at the Korea Masters Super 500 concluded on the opening day of the main draw in Suwon on Wednesday.
P V Sindhu bowed out, while H S Prannoy and Lakshya Sen scored hard-fought wins to advance in the Hong Kong Open Super 500 tournament.
Top seed and 2018 winner Shi Yu Qi of China dispatched Indonesia's Chico Aura Dwi Wardoyo 21-13, 21-8 while compatriot Li Shi Feng, world number six, came from behind to beat Canadian Brian Yang 21-11, 18-21, 21-16.
Prannoy fought back to level at 13-13, but Popov surged ahead as the Indian crumbled.
PV Sindhu is set to make a much-anticipated return to competitive badminton at the India Open Super 750 tournament after missing the season opener in Kuala Lumpur due to her wedding.
Treesa Jolly and Gayatri Gopichand (women's doubles) and B Sumeeth Reddy and N Sikki Reddy (mixed doubles) suffered three-game defeats in their opening contests.
Verma beat his Taiwanese opponent 21-18, 21-14.
India's men's singles campaign suffered a setback as none of the players could make it past the opening round on Day 2 of the India Open in New Delhi on Wednesday.
The duo of B Sumeeth Reddy and N Sikki Reddy entered the mixed doubles second round but the other Indian shuttlers, including Priyanshu Rajawat, made early exits
P V Sindhu advanced to the second round after her opponent Li Yvonne Li of Germany retired after the first game.
The world number nine will play Hong Kong's fifth seed Angus Ng Ka Long in the last eight stage.
Vietnam Open: Simran-Ritika in quarters.
Indian Mithun Manjunath stunned fourth seed and world number seven Kean Yew Loh of Singapore in the opening round while PV Sindhu and Kidambi Srikanth secured straight-game wins.
World champion Kunlavut Vitidsarn crashed out of the India Open Super 750 badminton tournament
Chinese swimmer Li Yang clocked 28.09 seconds to better the World record in the 50 metres backstroke at the 4th World Military Games in Hyderababd.
China and Spain played out a 0-0 draw in their final World Cup Group B match on Monday and the result was good enough for both teams to advance to the last 16 after Germany beat South Africa 4-0 in the other game in the section.
Third seeds China won the junior girls' title with an upset victory over India 'A', while top seeds India 'A' won the junior boys' crown, in the US $8000 Reliance India Junior and Cadet Open Table Tennis Championships, at the NSCI-Sardar Vallabhbhai Patel stadium in Mumbai on Thursday.