American teenage sensation Coco Gauff reached the first WTA final of her career on Saturday as the 15-year-old beat Andrea Petkovic 6-4, 6-4 in the last four in Linz.

Gauff, who burst onto the scene with a run to the Wimbledon last 16 earlier this year, is the youngest woman to make a WTA final since Nicole Vaidisova won the Tashkent title in 2004.

"This is definitely unreal, my first final on the WTA," said Gauff, who only got into the main draw in Austria as a lucky loser. "Linz is my special place.

"Not even in juniors did I ever get into something as a lucky loser -- now I'm in the final. I've had a lot of luck and happiness here."

The current world number 110 is set to climb to at least 80th in the rankings next week.

In Sunday's final, she will face 2017 French Open champion Jelena Ostapenko who saved three match points in beating Russian eighth seed Ekaterina Alexandrova 1-6, 7-6 (7/5), 7-5.

This is Gauff's first WTA tournament since she left the court in tears after a heavy defeat by two-time Grand Slam champion Naomi Osaka in the U.S. Open third round.

Gauff showed plenty of variety in her game as she beat the 75th-ranked Petkovic, relying frequently on well-executed drop shots.

The youngest-ever winner of a WTA Tour title was two-time U.S. Open champion Tracy Austin, aged just 14, at Portland in 1977.

Gauff saved nine of 10 break points and broke her opponent for 3-2 in the second set as Petkovic saved five break points before double-faulting on a sixth.

The American fought through in the final game to serve out victory, staving off three break points and coming through on her second match point.

Her mother arrived in time to watch her daughter, flying in from Luxembourg after arriving from Florida.

Gauff had thought she would be involved in Luxembourg WTA qualifying this weekend, but finds herself with more pressing duties in Linz instead.