China's Sun Yiwen shed a small tear of pride while the national anthem played after making history in the fencing competition at the Tokyo Olympics.

Later, she wept tears of sadness as she told reporters of her father's ill health back home.

The 29-year-old Sun on Saturday won China's first Olympic women's individual epee title by beating Romania's Ana Maria Popescu in overtime in the final.

Asked about her dad's condition in the post-match media conference, Sun covered her face as she welled up with emotion, much to the confusion of bronze medalist Katrina Lehis of Estonia, who sat next to her.

"This question is a little bit personal, maybe I can't answer," said Sun, before composing herself to open up about the situation.

"Only a month ago, the hospital issued a critically ill notice, he's getting treatment in Beijing and he's very sick.

"On the one hand, I have my love for my father. On the other hand, I wanted to do my country proud and compete.

"The doctor said maybe he has 10 days or at most a couple of months left. I'm very afraid I won't see him alive again, because when I go home I will have to quarantine once more, but I am on my own mission."

Sun later confirmed with Chinese media that her father's condition had stabilized.

"My whole family is trying to stay positive," she said.

At one stage during her closely fought final against Popescu, it looked as if Sun might let victory slip from her grasp.

With just 12 seconds left on the clock, she moved into a one-point lead to edge closer to glory. However, a last-gasp stab by the Romanian sent the bout to overtime to leave Sun's dream hanging in the balance.

Sun had suffered overtime heartache at the last Olympics in Rio, where, leading 11-7 in her semifinal, she let her advantage slip and eventually had to settle for bronze.

"When I had to face the overtime, I told myself it's OK and I can get the match-winning point," said Sun.

"I try not to think too much about the results, I just do as I have practiced so many times. So I did my best to stay calm and thankfully I won the game."

News of Sun's gold medal quickly became trending news on social media, before her emotional news conference endeared her even more to netizens.

True to her bubbly nature, Sun happily accepted interviews in the immediate aftermath of her victory, telling reporters about her "lottery mascot".

"I am a lucky girl," she said. "My friend likes to buy lottery tickets, and she can always win with me but can't win by herself!"

Sun, who helped China win team epee silver at the Rio Olympics, added: "I am very happy. After waiting five years I finally got my hands on the gold medal."