MELBOURNE, Australia -- Coco Gauff hopes she's got her "bad" match out of the way at the Australian Open before meeting defending champion Aryna Sabalenka in the semifinals.
It'll be a rematch of the U.S. Open final, which the 19-year-old Gauff won in three sets for her first major title.
Gauff is on a 12-match winning roll at the majors after rallying from 5-1 down in the first set to beat Marta Kostyuk 7-6 (6), 6-7 (3), 6-2 in a quarterfinal that lasted more than three hours.
Sabalenka is on a 12-match streak at Melbourne Park after her 6-2, 6-3 win over No. 9-seeded Barbora Krejcikova in the first match of the night session that didn't start until after 9 p.m.
"I love it. I love it," Sabalenka said of the showdown with Gauff. "After U.S. Open, I really wanted that revenge, and, I mean, that's a great match."
After winning her first major here last year, Sabalenka reached the semifinals at the French Open and Wimbledon before her run to the final in New York, finishing the year ranked No. 2.
In five rounds so far, she has dropped just 16 games and been on court for a total of 5 1/4 hours.
"I played great tennis," Sabalenka said after beating Krejcikova, the 2021 French Open champion. "I hope I can keep playing that way, or even better."
Gauff hadn't dropped a set until she faced No. 37-ranked Kostyuk, who ripped 39 winners but also made 56 unforced errors in a relentlessly attacking game.
"Today was definitely a C-game," Gauff said. "Didn't play my best tennis but really proud that I was able to get through. Hopefully got the bad match out of the way and I can play even better."
Gauff had 51 unforced errors, nine double-faults and had just 17 winners in a match containing 16 service breaks.
Her forehand was particularly vulnerable and Kostyuk took full advantage, racing to 5-1 only to show her own fragility with two double faults to hand back one of the breaks.
Gauff recovered to save a set point at 5-3 before leveling at 5-5. Kostyuk had another set point in the tiebreaker but couldn't convert.
The mistakes continued to flow, and though she led 5-3 in the second set, Gauff could not close it out. She was two points from victory at 6-5, 40-40, but Kostyuk held and took the tiebreak 7-3 to level.
The Ukrainian player said she was pleased to have made the quarterfinals at a Grand Slam tournament for the first time.
"Very proud of myself," she said. "I won for myself today and it's the most important thing. It's just the beginning of the season. Looking forward for what's ahead."