Tokyo (Japan), Aug 23 (IANS): Former World No 1 Saina Nehwal started her campaign in the BWF Badminton World Championships here on Tuesday defeating her rival in straight games in the first round.

She then got a walkover from sixth-seeded Nazomi Okuhara of Japan, who pulled out due to an injury, and stormed into the pre-quarterfinals in the women's singles.

The 32-year-old Saina, who won a silver medal in the 2015 World Championships in Jakarta and a bronze in 2017 in Glasgow, on Tuesday, stormed past Cheung Ngan Yi of Hong Kong, quelling her challenge 21-19, 21-9 in 38 minutes.

From 4-4 in the first game, Cheung Ngan Yi opened a small lead before Saina caught up with her at 10-10. Scores went neck-and-neck till 18-18 before Saina won the last few points to seal victory.

The second game was more one-sided as Saina, who enjoyed a 4-1 head-to-head lead over her rival, opened an early lead and kept her advantage throughout from 5-3 to build a lead of 14-8 and went on to seal the victory.

The women's doubles pair of Treesa Jolly and Gayatri Gopichand too advanced, beating Malaysia's Low Yeen Yuan and Valeree Siow 21-11, 21-13 in 37 minutes. Another women's doubles pair Ashwini Bhat and Shikha Gautam too made it to the second round, beating the Italian pair of Martina Corsini and Judith Mair 21-8, 21-14.

However, the mixed doubles pair of Ishan Bhatnagar and Tanisha Crasto went down to 14th seed Supak Jomkoh and Supissara Paewsampran of Thailand, 14-21, 17-21.

In men's doubles, the Indian pair of Krishna Prasad Garaga and Vishnuvardhan Goud Panjala lost to the French pair of Fabien Delrue and William Villeger 14-21, 18-21.

The mixed doubles pair of Venkat Gautam Prasad and Juhi Dewangan too was ousted despite putting up a tough fight in the second game, losing to England's Gregory Mairs and Jenny Moore 10-21, 21-23 in 28 minutes.