Despite wobbles, Coco Gauff advances to Australian semis

Coco Gauff advanced to her first career Australian Open semifinal on Tuesday, but it was far from a smooth journey.

The fourth-seeded Florida native defeated Ukraine's Marta Kostyuk 7-6 (6), 6-7 (3), 6-2 in a twist-filled quarterfinal that lasted 3 hours, 8 minutes.

"I'm really proud of the fight I showed today," Gauff said in her postmatch interview on court. "Marta's a tough opponent. Every time we play it's a tough match. Really fought and left it all on the court today."

Gauff, a 19-year-old who is the reigning U.S. Open champion, will oppose either second-seeded Aryna Sabalenka of Belarus or ninth-seeded Barbora Krejcikova of the Czech Republic on Thursday.

Kostyuk raced out to a 5-1 lead in the first set, but Gauff broke serve three consecutive times and saved a set point at 5-3. Gauff then failed to serve out the set at 6-5, forcing a tiebreaker.

Gauff jumped ahead 4-2 in the opening-set tiebreaker and had two service points coming when she led 5-3, but she lost both points. Kostyuk then failed on another set point on her serve, and Gauff eventually prevailed 8-6.

The second set featured six service breaks before Kostyuk won the first four points of the tiebreaker and sailed to a 7-3 win.

The third set was one-sided, with Gauff cruising to a 5-0 lead before closing out the match.

"I was just trying to get one more game in the first set and at least make it competitive," Gauff said. "And then one game turned to another and I was able to win that set. And then in the second, I put myself in an opportunity (to win). I think I got a little bit passive.

"When I came out in the third, I was just trying to play aggressive and hit through the court because I knew if I left something standing, she was going to take advantage."