Women's top seed Nozomi Okuhara breezed through as main draw action began at the Badminton World Federation German Open.
The 2017 world champion and Rio 2016 bronze medallist defeated Denmark's Line Kjærsfeldt 21-8, 21-10 at the Super 300 tournament.
There was no such luck for Canada's sixth seed Michelle Li at the Innogy Sporthalle in Mülheim as she suffered a first round exit.
Li, the Glasgow 2014 Commonwealth Games champion, lost 23-21, 21-19 to Japan's Aya Ohori.
In the men's draw, double Olympic gold medallist Lin Dan was among those to progress.
The Beijing 2008 and London 2012 champion won an all-Chinese duel with Lu Guangzu, 21-16, 25-23.
Top seed and reigning world champion Kento Momota of Japan beat Wang Tzu-wei of Chinese Taipei 21-18, 21-15.
Third seed Kenta Nishimoto of Japan also made it through by defeating Brazil's Ygor Coelho de Oliveira 21-17, 21-16.