MELBOURNE, Australia -- Magda Linette has been knocking on the door of the second week at a major for years, but it took her 30th main-draw appearance at a Slam to finally break through. 

The 30-year-old from Poland paved her way to her first major quarterfinal at the Australian Open by defeating three seeds in succession.

After defeating No.16 Anett Kontaveit and No.19 Ekaterina Alexandrova, the World No.45 stunned No.4 Caroline Garcia 7-6(3), 6-4 in the Round of 16 on Monday. The win the third Top 5 win of Linette's career. 

Match report: Linette shocks WTA Finals champion Garcia

"I wasn't that completely far away [from the second week," Linette told reporters. "In Wimbledon, I was quite close one year to get through to the second week when I was kind of having a break up in the third set against Paula [Badosa]. When I was at the Roland Garros, I was set up against Ons [Jabeur]. I've been in the third rounds for so many times that I knew I'm capable.

"Then when I start beating players like Ash Barty and then Ons, that kind of gave me an extra kick that really showed me that I can really go far in those tournaments. I think it was more frustrating than I would wonder or worry about it. I think it was just more frustration why I can't do it."

Throwback: Linette takes the logical path to success

"Dealing with some kind of losses, not necessarily match losses, just even throughout the match 'losses', like small mistakes here and there, I think I've never really dealt with them very well."

As she asked herself the question, Linette and her team began to focus on her emotional control. A talented all-court player who could trouble any player on any given day, Linette had a history of letting one bad point or game derail her mind. The negativity was weighing her down. Last summer, she said enough is enough. 

"Dealing with some kind of losses, not necessarily match losses, just even throughout the match 'losses,' like small mistakes here and there, I think I've never really dealt with them very well. They carried over later on to the next point, then another one. It was taking me just too long to get over them.

"Of course we worked so much on my game. We worked a lot on changing the directions and the depth of the ball. But I think this approach of really trying to look a little bit different, grow up a little bit emotionally, that was a big thing for us as a team."

Break Point: Netflix

Follow the Stars

The fruits of the team's labor weren't immediately realized but the progress was there. Linette made the final in Chennai last fall, followed by a quarterfinal run in Seoul. But Linette says the turning point came during her title run at the WTA 125K in Tampico, Mexico in October. 

"In the first set, I was playing one girl, and she was giving me a lot of trouble. I completely broke in tears in the first set. My coaches were really surprised by that. 

"I felt like I threw all that anger out of me. That was the last time when I really lost it. Since then I really controlled it better."

Since then, Linette has shown her ability to step up to pressure and maintain her focus. At the Billie Jean King Cup Finals in November, she went 2-0 with wins over Karolina Pliskova and Madison Keys. 

Australian Open: Linette gets first Slam quarterfinal, third Top 5 win

An intentionally abbreviated offseason meant she felt fresh and still in competition mode when the new season began. At the United Cup, she bore the weight of playing two crucial matches for Poland, securing the tie against Switzerland with a win over Jil Teichmann and with a victory against Lucia Bronzetti to give Iga Swiatek and Hubert Hurkacz the chance to seal the win for Poland over Italy in mixed doubles. 

"We did a little bit easier preseason than usual," Linette said. "I was usually really working very hard physically. This time we took it a little bit different. We kind of thought, 'OK, I'm not that young anymore, I'm after one surgery, so we need to really be careful about how we approach this.' I think I'm so much fresher."

Linette will face former No.1 Karolina Pliskova in the quarterfinals, a rematch of their Billie Jean King Cup showdown, in which Linette won 6-4, 6-1. Pliskova leads the overall head-to-head 7-2, but Linette backs her chances if she can keep her emotions at bay.

"It's very difficult. I'm 31 and I'm just getting it right, so obviously it was one of the toughest things for me," Linette said. 

"But I'm happy. I'm happy that I have this opportunity, that actually I tapped into something that finally I'm breaking something that you can't really measure in any way. For me, it was something really difficult to change."