Melbourne - Coco Gauff's bid for history at the Australian Open ended in tears in the last 16 on Sunday as the 15-year-old crashed out in three sets to fellow American Sofia Kenin.
The 14th seed Kenin recovered from a set down to win convincingly 6-7 (5/7), 6-3, 6-0 and Gauff left the court crying.
Kenin plays Tunisia's unseeded Ons Jabeur after she defeated China's Wang Qiang to become the first Arab woman to reach a Grand Slam quarter-final.
"I just did the best I can. I just tried to take it like any other match," said Kenin, who also had tears in her eyes afterwards.
"I know she's (Gauff) playing well, I just tried to play my game and fight for every point and just not focus on anything else."
Gauff, the youngest player in the draw, has been one of the stories of the Australian Open, beating Venus Williams in the first round and then stunning reigning champion Naomi Osaka in round three.
The supremely talented teenager, who turns 16 in March, was attempting to become the youngest player to win a Grand Slam in the Open Era, which began in 1968.
The current record-holder is Martina Hingis, who triumphed at the 1997 Australian Open at 16 years old and nearly four months.
Gauff was under the cosh immediately against Kenin, the 21-year-old breaking in the first game at Melbourne Arena and comfortably holding for a swift 2-0 lead.
There was no mistaking who the crowd wanted to win - each point for Gauff greeted with cheers and screams; there was only polite applause for Moscow-born Kenin.
The 67th-ranked Gauff recovered to gain parity for 4-4 and they went to the tie-break after Kenin saved set point.
Gauff then stepped it up a gear in the tie-break - aided by two Kenin double-faults - to take the first set in 58 minutes.
The younger American's serve is powerful but she was totting up the double faults, her seventh of the match offering Kenin a second break point with the latter 2-1 up.
A resurgent Kenin - the determination etched on her face - broke at the third time lucky to lead 3-1, triggering a rare show of anger from the teenager.
Kenin took the second set in 38 minutes and carried the momentum into the deciding set, breaking Gauff to love in the opening game and racing towards victory.
Touted as heir apparent to Serena Williams, Gauff burst onto the scene when she beat Venus Williams in the Wimbledon first round last year on her Grand Slam debut.
She went out in the fourth round to eventual champion Simona Halep, but a star was born.
Gauff lost to then-number one Osaka in the third round at the US Open, but got her revenge at the same stage in Melbourne, more evidence of her huge potential.
That made Gauff the youngest player to defeat a reigning Australian Open champion in the Open Era.
Collated results on day seven of the Australian Open Grand Slam at Melbourne Park on Sunday (x denotes seeding):
Milos Raonic (CAN x32) bt Marin Cilic (CRO) 6-4, 6-3, 7-5
Novak Djokovic (SRB x2) bt Diego Schwartzman (ARG x14) 6-3, 6-4, 6-4
Tennys Sandgren (USA) bt Fabio Fognini (ITA x12) 7-6 (7/5), 7-5, 6-7 (2/7), 6-4
Roger Federer (SUI x3) bt Marton Fucsovics (HUN) 4-6, 6-1, 6-2, 6-2
Petra Kvitova (CZE x7) bt Maria Sakkari (GRE x22) 6-7 (4/7), 6-3, 6-2
Sofia Kenin (USA x14) bt Coco Gauff (USA) 6-7 (5/7), 6-3, 6-0
Ons Jabeur (TUN) bt Wang Qiang (CHN x27) 7-6 (7/4), 6-1
Ashleigh Barty (AUS x1) bt Alison Riske (USA x18) 6-3, 1-6, 6-4