Current world number two and reigning All England champion Chen Yufei advanced into the quarter-finals of the Badminton World Federation Swiss Open in Bsael but was pushed all the way by Estonia's significantly lower ranked Kristin Kuuba.
In her second match at the St. Jakobshalle, 21-year-old Chen, the 2017 World Championship bronze medallist, needed three games to beat world number 71 Kuuba in the World Tour Super 300 event.
After a tense battle the final score read 21-12, 20-22, 21-13 in Chen's favour, meaning she will now face India's Riya Mookerjee in the last eight.
She is hoping for a second tournament win in a row after winning the All England in Birmingham last week.
Mookerjee, who is ranked down at 110th in the world, made it through without having to finish her match as her opponent, Canada's Michelle Li, retired before the end of the first game.
Another to make it through was Beiwen Zhang from the United States.
In a more comfortable straight games contest the world number 12 saw off Denmark's Julie Dawall Jakobsen 21-7, 21-16.
She will now play Japan's Ayumi Mine who triumphed over Germany's Yvonne Li 23-21, 21-19.
Others to make it through include Russia's 2018 European silver medallist Evgeniya Kosetkaya who is seeded eighth and Spain's Clara Azurmendi.
They advanced with wins by scores of 21-18, 21-19 and 21-7, 18-21, 22-20 respectively.
In the men's singles the top seed also advanced, but for the second day in a row Shi Yuqi had to do it the hard way.
After battling through a three game match in round one yesterday, the Chinese world number two had to come from behind to beat Brazil's Ygor Coelho today.
The result read 16-21, 21-15, 21-11.
At the Lingshui Masters, taking place simultaneously at Agile Stadium in the Chinese city, there was a surprise result as top seed Ihsan Maulana Mustofa crashed out of the men's singles in round three.
The Indonesian world number 40 was beaten in round three, 21-14, 13-21, 9-21 by Malaysia's Iskandar Zulkarnain.
There was no such surprise in the women's singles, however, as China's top seed Yiman Zhang saw off South Korea's Yeong Kim Na 21-19, 19-21, 21-16.
The event is a Super 100 tournament.