China and Japan breezed into the quarters of the Thomas and Uber Cups with unblemished records Wednesday, making their case as the main rivals for the men’s and women’s badminton tournaments.

Desperate to regain the Thomas Cup, China’s men have taken every point from their opponents, with Olympic star Chen Long leading from the front with three wins, helping his country to 5-0 wipeouts of Australia, France and India.

The women’s side, defending champions who have conceded only one Uber cup since 1998, edged Indonesia 3-2 on Wednesday to keep their clean record into the knockout rounds.

But glory is not guaranteed for the squad this year with Olympic champion Li Xuerui yet to find her form after returning from a lengthy injury lay off.

She lost to Indonesia’s Ruselli Hartawan 15-21, 21-19, 21-18 on Wednesday.

“I’m just getting acclimatised to the courts,” she said of her loss, according to a Badminton World Federation press release.

“China had already won the tie so maybe I didn’t feel the urgency. I would have done better if it was a deciding match.”

Top seeds Japan are in menacing form, swatting away India on Wednesday 5-0 with stars Akane Yamaguchi and Nozomi Okuhara once again doing the business in the singles, with Misaki Matsutomo and Ayaka Takahashi securing the points in the doubles.

The men are also in fine form, overpowering Taiwan 5-0 Wednesday morning after two 4-1, 4-1 victories earlier in the week.

Thailand’s women have so far delighted the home crowd, battering both Germany, Hong Kong in their first two ties as they aim to be seeded in the draw for the quarters.