Howard Shu secured a place in the men's singles main draw ©Getty Images

Howard Shu battled through qualification to reach the main draw at the U.S. Open Badminton Championships in Fullerton, California.

The American, a Rio 2016 Olympian, impressed in his first round men’s singles match at the Badminton World Federation Super 300 event.

He overcame the challenge of Trinidad and Tobago’s Nicholas Bonkowsky 21-16, 21-8 to advance to a second qualification match at the Titan Gym on the campus of California State University

Shu was handed a tougher test against Canada’s B.R. Sankeerth, with their match going to three games.

The home athlete clinched victory in a nervy final game, emerging as a 21-17, 9-21, 23-21 winner.

There was disappointment for Phillips Jap, with the American falling to a 19-21, 21-17, 21-10 loss to South Korea’s Yun Kyu Lee in his qualification match.

In the women’s singles draw, Crystal Pan overcame Sweden’s Johanna Magnusson 21-18, 21-13 to reach the main draw.

Her fellow American Lauren Lam also progressed with her opponent Debora Vehrenica of Indonesia having retired when trailing 21-17, 19-19.

Chinese players also progressed, with Li Xuerui beating the United States’ Natalie Chi 21-7, 21-14 in their qualification match.

Li’s compatriot Lu Guangzu then won 21-17, 21-15 against South Korea’s Ha Young Woong.

Two-time Olympic champion Lin Dan of China is the top seed for the men's singles event.

Defending champion Prannoy Kumar opted not to defend his title, with the Indian targeting bigger events.

Beiwen Zhang will be hoping to deliver victory in front of her home crowd as the American is seeded top in the women's singles tournament.