Facing a Chinese player who is also the world's number 9, Chen Yufei, Gregoria was able to force her opponent a three-game battle before finally securing a victory, 17-21, 21-19, and 21-19.

The two players have previously met in the final of 2016 Asia Junior Championships. At that time, Grego had to admit Chen's superiority after losing 23-25 and 14-21.

"I learned a lot from the AJC defeat. I just played defensively since that made the opponent slightly weak. I'm surely happy to pay back," said Gregoria after the match.

Steep road ahead of her in the second round tomorrow. That is because the Taiwanese first seed, Tai Tzu Ying is already waiting for him.

"I just want to play without burdens since the rank gap is pretty poles apart. But I refuse to give up before fighting because I have prepared well before coming here," said Gregoria.

"I already know the opponent's style more less because I often saw her playing. One thing for sure, I should be able to stand with her shots and not to rush," Gregoria added.