The Rio 2016 singles gold medallist, seeded first for this competition, was forced to come back from one game down to win against Line Kjaersfeldt at the innogy Sporthalle in the Grand Prix Gold level event.

The Danish player took an early lead, winning the opening game 21-19.

Marin, the double world champion and current world number two, showed her class as she came back to secure her place in the next round winning the next two games 21-11, 21-11.

Joining her in round two is Japan's Akane Yamaguchi.

The second seed beat Mette Poulsen of Denmark 21-19, 21-19.

Thailand's Busan Ongbamrungphan also made it through after she eased to a 21-11, 21-10 over Natalia Perminova of Russia.

China's Lin Dan was a comfortable winner in the men's singles draw.

The third seed swept aside Mateusz Dubowski of Poland 21-14, 21-16.

He  is now due to meet Emil Holst of Denmark in the third round after he proved too strong for 11th seed Wing Ki Vincent Wong of Hong Kong.

Wong lost out to the unseeded Holst 21-18, 21-18.

Fabian Roth of Germany provided some delight for the home crowd as he defeated Sweden's Henri Hurskainen 21-13, 16-21, 21-17.

There was a shock in the men's doubles as top seeds Takeshi Kamura and Keigo Sonoda of Japan were beaten.

The Danish pair of Mathias Christiansen and David Daugaard, who are unseeded, collected an unexpected 21-15, 25-23 win.

The favourites in the women's doubles competition, Japan's Naoko Fukuman and Kurumi Yonao, had no such problem as they breezed into round two with a 21-19, 21-9 win over Maiken Fruergaard and Sara Thygesen of Denmark.