Eighteen-year-old Egyptian Mostafa Asal continued his fine run at the Professional Squash Association (PSA) Tournament of Champions by defeating France's 2015 world champion Gregory Gaultier in New York City.
The teenager knocked out world number nine compatriot Mohamed Abouelghar in the previous round and enjoyed a 5-11, 13-11, 12-10, 10-12, 11-5 win over Gaultier in round three.
It has booked him a first quarter-final at a PSA World Tour Platinum event, with reigning world champion Tarek Momen awaiting in the last eight.
Thirty-seven-year-old Gaultier, a former world number one, exits the tournament at Grand Central Terminal after making a superb return to the circuit.
He spent 15 months on the sidelines due to a knee problem but beat Egypt's former world number three Omar Mosaad in five games in round two, in a repeat of the 2015 world final.
"Gaultier is such a legend, and I can't describe the feeling of sharing a court with him," said Asal.
"I remember when I was 13-years-old, I went on court to practice with him, every single day after his matches in El Gouna, so I want to thank him for the opportunity to play with him.
"He really is a legend and I can't describe my feelings to him.
"I was a child and I texted him to ask if I could play with him in El Gouna and he said yes.
"I know if he hadn't have been injured then he would have finished me in about five minutes.
"It's unbelievable to play here, it's my second home, and it's the best tournament that I have ever played on the PSA."
Fellow Egyptian Momen, seeded fourth, beat Malaysia's Eain Yow Ng 11-9, 11-4, 3-11, 11-9 to book his quarter-final place.
Egypt's top seed Ali Farag, the defending champion, knocked out compatriot Youssef Soliman 11-9, 11-9, 11-7 and New Zealand's fifth seed Paul Coll saw off England's Tom Richards 11-5, 12-10, 11-1.
In the women's second round, two home American players advanced at the expense of seeded opponents.
Sabrina Sobhy saw off England's 15th seed Victoria Lust 10-12, 11-6, 11-9, 12-10 and Olivia Blatchford Clyne went through when Welsh ninth seed Tesni Evans retired in the first game.
Egypt's title holder Nour El Sherbini, the second seed and reigning world champion, saw off Dutch player Milou van der Heijden 11-4, 11-8, 11-4.
Her compatriot Nour El Tayeb, the fourth seed, beat Australia's Donna Lobban 11-8, 11-9, 11-6.
The tournament continues tomorrow.