The Dane defeated Chun Yi Lin from Taiwan in three very close sets, with Antonsen securing his progress through a 21-19, 20-22, 22-20 win.
In the third set, it finally seemed like Antonsen seized the momentum and could secure the win comfortably, but a linesman's controversial call against the Dane gave rise to great frustrations.
However, Antonsen got back on track and secured his access to the quarter-final, where he will face the 26-year-old Frenchman Toma Junior Popov.
Here he is, the only Danish player left in the big tournament in all categories.
On Thursday, the mixed doubles with Mads Vestergaard and Christine Busch first went out in two sets against an Indonesian pair, and later Mads Vestergaard was on the losing side again - this time in men's doubles together with Daniel Lundgaard.
The Danish men's doubles team lost in two sets to a South Korean pair.