What started as a pipe dream at the beginning of the year is now a reality for American teenager Coco Gauff.

Ranked outside the Top 600 in January, the 15-year-old aspired to crack the Top 100 in the WTA rankings in 2019 -- and after taking the sporting world at large by storm in the months since, she's done that and more. 

The American added to her already-growing "youngest since" portfolio by capturing the title at the Upper Austria Ladies' Linz over the weekend, becoming the ninth-youngest player to ever win a WTA singles title.

Not only did she become the youngest title-winner on tour in 15 years, she is the youngest American to raise a tour trophy since 1991, and the second lucky loser to win a singles title in the past 18 months.  

Coupled with her Grand Slam breakthroughs and Wimbledon and the US Open this season, the 15-year-old's maiden triumph hoisted her to a career-high ranking of World No.71 in Monday's latest rankings update

"This year has been a whirlwind, and I guess this is a cherry on top," Gauff told wtatennis.com by phone from the BGL BNP Paribas Luxembourg Open on Monday.

"Last week was great. I definitely didn't expect it, considering I got in as a lucky loser. At the beginning of this year, I never thought that around this time, I'd be winning my first title.

"I've accomplished all my goals this year that I wanted to do. Winning a title wasn't on my list this year, but I'm glad it happened."

Though she raised the trophy on the last day of the tournament, Gauff's campaign in Linz was nearly over on the first Sunday, after she lost to German Tamara Korpatsch in the final round of qualifying.

On site to practice and for a media event on Monday, the 15-year-old got a second chance when Maria Sakkari, set to be seeded No.6, withdrew with a wrist injury, and got just under an hour's notice that she would take the Greek's place against Swiss Stefanie Voegele.

Read more: Gauff vanquishes Voegele in second shot at Linz

"After I realized that I got in as a lucky loser, I was relieved, and I played more free. Every match was lucky and a blessing after that because I was supposed to be out of the tournament," Gauff said.

"When I lost the qualifying match, my team and I felt like I was rushing out of the points too much and trying to overhit the ball. My body language could've been better, and my attitude on the court.

"I took that into account and I used what I learned in the next matches. My goal wasn't really to win after that - my goal was to improve from my last matches, improve my behavior and attitude. They did, and that improved my results."

Gauff and her parents, Candi and Corey, with the Linz trophy. (Getty)

Having scored just one victory over a Top 50 player amongst her prior runs this year - her Cinderella debut against idol Venus Williams at Wimbledon - Gauff added several notable victories to her resumé in Austria. 

She not only scored her first Top 10 victory in Linz, against Kiki Bertens in the quarterfinals, but also beat former Top 10 player in Andrea Petkovic in semifinals, and former French Open champion Jelena Ostapenko for the title. 

"As every match [in Linz] went on, I gained more and more confidence in my strokes. I played some tough opponents, so my confidence is doing well, and is high right now," she said.

"I try to treat every match similarly. Obviously, you play different players and you adjust to their playing style, but I try to go into every match with the same mindset.

"Even though some players may be more experienced that other or may have better results, you never know how someone is going to play that day when you play against them. Every day is a new day. 

"My grandfather always tells me that anyone can win a match on any day regardless of the past, so I try to treat every match and every opponent similarly, despite who might have a higher ranking or Grand Slams, or not."

Read the match report: 'It’s been an unbelievable week for me' - Gauff grabs first title, defeats Ostapenko in Linz

While she keeps a piece of advice from her grandfather close to heart in her matches, it was some words of wisdom from her father and coach, Corey, that helped Gauff get over the line in the final against Ostapenko.

After seeing two match points slip away with a 5-0 lead in the final set, Gauff called out her father at the ensuing changeover, and the elder Gauff settled his daughter down by telling her take the pressure off, and picture herself on their home courts in Delray Beach, Fla.

Gauff's coaching from her father Corey in the final went viral in Linz. (©Jimmie48/WTA)

"He just told me everything I needed to hear. I was a little bit reluctant, because in the moment I was just so mad that I had two match points [at 5-0] and I didn't get that game," she said with a laugh.

"He did a good job. He gave me the best advice. I guess he didn't really tell me how to play - just to stay calm and stay focused - even though I wanted him to tell me how to play, he didn't need to tell me what side, what spot to hit to because I was already up 5-2 in the third set.

"After the match, he told me that he knew that I already knew what I needed to do to win, but he was just trying to calm me down. I think he could tell that I was a little bit anxious, because it was close to the end of the match. He calmed me down, and it worked."

Now securely in the Top 100 as the season winds down, Gauff is looking to keep the good vibes rolling in her final tournament of 2019. 

She will aim for her sixth straight win as she takes on No.8 seed Anna Blinkova of Russia in the first round in Luxembourg on Wednesday, and is also in the doubles draw alongside Catherine McNally.

"I've seen [Blinkova] play a couple of times, and I know she's young. I think it will be a pretty good match," Gauff said.

"I'm just going to continue to improve my game, and hopefully do well in singles and doubles to finish off the year strong. After this tournament I'm going to have a little bit of a break, vacation a little bit, get ready for preseason and focus on school."

Gauff and McNally reached the semifinals in Linz in doubles. (©Jimmie48/WTA)

And this week, there might be a fair bit of studying going on in the players' lounge in Luxembourg: a total of four rising American teenagers made the trip to the tournament, as Gauff and McNally were joined in the draws by Katie Volynets and Elizabeth Mandlik.

With an eye turned towards 2020 already, the Floridian thinks that the surge of young American talent is no accident. 

"I think it's an exciting time for American tennis. Katie Volynets and Caty McNally, we've known each other for a long time. The first time I played Katie Volynets, I think I was 10, and she was 12, at nationals or something," Gauff said.

"We all just played with each other, went to USTA camps together, training with each other, and I think we all push each other to do better. We're competing against each other, but also rooting for each other. We want each other to do well.

"When we're competing against each other, we want to win, but I think that since Amanda [Anisimova] made the semifinals of the French Open, that gave me a little bit of inspiration.

"That was part of the reason, I guess, why my Wimbledon run happened - because she was a young American who we grew up playing with, and she did well at a Grand Slam.

"It gave us belief that we could do it at an early age, and not have to wait until later in our careers to do it."