Cori Gauff missed out on reaching her maiden Grand Slam quarter-final with a fourth-round defeat by fellow American Sofia Kenin at the Australian Open.
The 15-year-old, who came to prominence by reaching the last 16 at Wimbledon last year, was bidding to become the youngest player to reach a Grand Slam quarter-final for 15 years.
Gauff showed her battling qualities to recover from losing her serve in the opening game of the match to win the first set, before Kenin eventually proved too tough in a 6-7 (5-7) 6-3 6-0 victory on a packed Melbourne Arena.
Kenin said: “It was such a tough match, she’s such a tough player, all respect to her.
“It means a lot to me, I’m so happy to be through to the next round. I just tried to play my game, fight for every point and not focus on anything else.”
Kenin, 21, who had not progressed past the second round on her previous two visits, will face Tunisia’s Ons Jabeur in a meeting between two first-time Grand Slam quarter-finalists.
Jabeur defeated China’s Wang Qiang, who shocked seven-time champion Serena Williams in the previous round, 7-6 (7-4) 6-1.
Kenin, who knocked out Williams at the French Open last year, opened up a 4-2 lead with her early break but was pegged back to 4-4 by Gauff through her greater power from the back of the court.
Gauff had a set point at 5-6, but it was saved well by Kenin, but two double faults in the tie-break from the 14th seed proved costly and, although she saved three more set points, the teenager eventually sealed the first set on her fifth set point.
Kenin recovered to win the early break in the second set as Gauff double-faulted three times to drop serve in the fourth game, before the 21-year-old took control, winning nine of the next 11 games to complete victory.
Gauff said: “My short-term goal is to improve. I’m doing well right now at 15.
“I still have so much I feel like I can get better on. Even my parents, my team, they all believe I can get better. I don’t even think this is close to a peak for me.”
Petra Kvitova battled back from a set down to defeat Greek Maria Sakkari 6-7 (4-7) 6-3 6-2 and reach the last eight in Melbourne for the fourth time in her career.
The Czech 2019 finalist trailed by a break in the second set but responded to claim breaks in the seventh and ninth games to force a deciding set.
Kvitova, who had lost two of her previous three meetings against Sakkari, maintained the ascendancy as two further breaks completed victory for the two-time Wimbledon champion.
“I didn’t feel the best. I was just, you know, too tight and everything was flying somewhere…” said Kvitova, who broke Sakkari eight times and hit 33 winners.
“In the end of the day, it was about fighting spirit in a way. Even I didn’t play the best, Maria played really great tennis, and it was nice to share court with her, for sure… I’m so happy that in the end I felt my game again.”
Kvitova will next face the winner between world No 1 Ashleigh Barty, who defeated American 19th seed Alison Riske 6-3 1-6 6-4 in the opening match of the night session on Rod Laver Arena.
Barty started the strongest and had two break points for a 4-0 lead, but despite a recovery from Riske the Australian won the first set in 34 minutes.
However, Riske, who was playing in the fourth round for the first time, started on the front foot in the second set and broke twice to force a third set.
Riske, who won in each of the previous two meetings, recovered from a break down in the decider but could not maintain her standards and served a double fault on Barty’s first match point.