(Photo credit: Geoff Burke-Imagn Images)

In a hectic day where all seeded players lost, No. 2 Tallon Griekspoor of the Netherlands fell at the hands of 21-year-old Frenchman Luca Van Assche 6-4, 1-6, 6-3 in Thursday's round of 16 action of the Grand Prix Hassan II in Marrakech, Morocco.

It took over two hours for Van Assche to take down last year's finalist in this event to reach just the third tour-level quarterfinal of his career. Van Assche was clinical on Griekspoor's second-serve points, converting on 23 of 36 (64%) while Griekspoor struggled, converting on just 10 of 27 (37%) on Van Assche's serve. Griekspoor had more winners (43-18) and saved more break points (4-3), but also had five times as many unforced errors (50-10).

In the next round, Van Assche will face Argentinian Camilo Ugo Carabelli after he pulled off an upset of his own by taking down seventh-seeded Peruvian Ignacio Buse 6-3, 3-6, 7-5. Fourth-seeded Tomas Machac of Czechia also lost, with Spain's Rafael Jodar coming away with a 6-4, 4-6, 6-3 win. Jodar converted four of his six break-point opportunities en route to the win.

France's Alexandre Muller took down sixth-seeded Czech competitor Vit Kopriva in straight sets 6-3, 7-6 (3) and will face Jodar. Top-seeded Italian Luciano Darderi advanced to the semifinals after eighth-seeded German Yannick Hanfmann withdrew before the match was set to be played tomorrow due to an illness.

U.S. Men's Clay Court Championship

Five Americans will be in action during the round of 16 in Houston, Texas, and fifth-seeded Brandon Nakashima was the first to fall as he lost 6-4, 2-6, 6-4 to Argentina's Roman Andres Burruchaga in a two-hour, eight-minute match.

Burruchaga was able to tear apart Nakashima's serve as he converted on four of five break-point opportunities and saved four breaks of his own. Burruchaga will face third-seeded Learner Tien, who beat fellow American Nishesh Basavareddy 6-3, 3-6, 6-1 behind a stellar serving performance which saw him broken just once while saving six of seven break-point opportunities.

The remaining matches of the day are between second-seeded American Frances Tiafoe and Australian Rinky Hijikata as well as seventh-seeded American Alex Michelsen and Alexei Popyrin of Australia.

Tiriac Open

Second-round play was suspended in Bucharest, Romania due to inclement weather. Only one match was started and it lasted only a few minutes before play was suspended.

--Field Level Media