On Saturday, the 15-year-old tennis star defeated Andrea Petkovic 6-4, 6-4 at the Linz Open in Austria to move on to the final round of the tournament.
The teenage sensation secured a 6-4 6-4 victory to continue her phenomenal breakout year and become the youngest player to reach a WTA final since Czech Nicole Vaidisova in 2004.
Gauff, who is now ranked 110th in the world, lost the opening two games of the match, but then didn't look back as she claimed the first set 6-4 before a more straightforward 6-4 second set win to secure her final spot. Andrea hit a lot of winners and put pressure on me.
But she only got into the event as a lucky loser after an injury to former Wimbledon victor Angelique Kerber. "I guess Linz is my special place, giving me a lot of luck and a lot of happiness here".
"This is actually the first time in my life, including juniors, that I got into something as a lucky loser, and now I'm in the final", said Gauff.
'This was one of the highest-level matches I've played. "I thought I was out in qualifying and now I'm here".
Then as a wildcard at her home major, the US Open in August, it took the defending champion, Naomi Osaka, to stop the Florida resident in the third round.
Gauff showed great defense and mixed up her game impressively, making Petkovic pay for a double fault which gave the teenager a 3-2 advantage in the second set.
"I'm not the most confident with it but it worked well today", she said.
Her ranking will climb from its current 110th to around 80th even if she loses Sunday to either 2017 French Open champion Jelena Ostapenko or Russia's Ekaterina Alexandrova, meaning Gauff will earn a direct spot into the next grand slam, January's Australian Open, instead of having to go through qualifying or needing a wildcard. "I think I'll keep using it until it doesn't work so well anymore".
It was a mighty close encounter and Gauff had the upper hand in the pivotal moments, fending off both break points she faced and taking the opening set with a dominant 7-1 display in the tie break.
The youngest-ever victor of a WTA Tour title was two-time US Open champion Tracy Austin, aged just 14, at Portland in 1977.
"This is insane, I thought I was out of the tournament in qualifying", said the American.