No. 14 seed Sofia Kenin rallied to beat fellow young American star Coco Gauff 6-7 (5), 6-3, 6-0 to advance to the quarterfinals on Sunday at the Australian Open in Melbourne.
Gauff, 15, was coming off a historic upset of defending champion Naomi Osaka in the third round.
With the victory, Kenin, 21, reaches the quarterfinals of a grand slam for the first time.
"Obviously it meant a lot to me," Kenin said. "I was just so happy to have won. It was a tough match. I knew (Gauff was) playing well. I was just really happy with the way that I was able to handle my emotions and just fight through every point."
Gauff pulled off her only service break of the match in winning a tight first set, but Kenin buckled down and controlled the final two sets in the two-hour, nine minute victory.
"I knew it was a few minor details," Kenin said. "I felt like I wasn't returning so well. I missed a few opportunities. Of course, she served really well."
Gauff finished with seven aces, but struggled with 48 unforced errors after making just 17 against Osaka.
"I'm definitely going to savor this and continue to kind of build and get better to work for moments like this, moments like that last match," Gauff said.
Also making the quarterfinals was No. 1 seed Ashleigh Barty of Australia, who beat No. 18 seed Alison Riske of the United States 6-3, 1-6, 6-4 after losing to her in both of their previous matches.
Afterward, Barty noted the windy conditions made play difficult.
"I think end to end was very different," Barty said. "The breeze is always a little bit different at court level than it is kind of up in the stands. Tonight was stronger than the other days. It was just about adapting and trying to work through it as best as you can. It was important to try and hold and stay and fight for every point from the end where you were against the wind, and make the most of it when you were with the wind."
Next up for Barty is No. 7 seed Petra Kvitova of the Czech Republic, who held off No. 22 seed Maria Sakkari of Greece 6-7 (4), 6-3, 6-2.
Kenin will face Ons Jabeur in the quarterfinals after the Tunisian beat China's Qiang Wang, the No. 27 seed, 7-6 (4), 6-1.
Jabeur becomes the first Arab woman to reach a Grand Slam quarterfinal.
"Quarterfinals for the first time, trying to inspire many young generation back home either in Tunisia or the Arabic world, especially in Africa, which is amazing," Jabeur said.
--Field Level Media