Getting to the pointy end of the year's first Grand Slam was not a specific goal for the 23-year-old, but instead she has focused on keeping her emotions in check after battling personal challenges, which she did not want to talk about.
"I was just trying to enjoy playing here," Yastremska told reporters after beating Czech teen Linda Noskova 6-3, 6-4.
Fresh attacks on Ukraine add to the weight on the shoulders of the world number 93, who revealed at an Australian Open lead-up tournament in Brisbane that just before one of her matches, her grandmother's house had been hit by a rocket.
At Melbourne Park, she has been undaunted by higher-ranked players across the net, beating former Australian Open champion Victoria Azarenka and reigning Wimbledon champion Marketa Vondrousova along the way.
"The girls, you know, at any ranking can show amazing game," she said.
"I was doing just my thing and focusing on myself, the way I play. I think that's working."
On her way off the court, Yastremska, dressed in blue and yellow matching her country's flag, scribbled on the camera: "I'm proud of our fighting people from Ukraine."
She later said the fighters deserve huge respect.
"I think it's my mission here," she told reporters. "If I do well, I can get - (it's) tough to express. I'm just trying to give the signal to Ukraine that I'm really proud of it."
In the wake of Moscow's war on Ukraine, Ukrainian players on the tour have refused to shake hands with opponents from Russia and Belarus, which has been used as a staging ground for Russian attacks.
However, Ukrainian junior Yelyzaveta Kotliar caused a stir when she shook hands with her Russian opponent after losing her first-round match this week. Yastremska called it a youthful mistake.
"You know, Ukrainians, we have our position. We are not shaking the hands. But I think she's still a little bit young. Not so experienced," Yastremska told reporters.
"But I'm sure that she stands by Ukraine, and I'm sure that she just got too emotional and confused."
Yastremska is not letting tennis get in the way of her musical ambitions. She is working on releasing a song with two other people in February which she said would bring together three countries.
"You're going to hear it soon, I hope."
