ATP roundup: Top seeds challenged in Marrakech

No. 1 seed Tallon Griekspoor of the Netherlands needed three sets to advance to the quarterfinals, while No. 2 seed Lorenzo Sonego of Italy was ousted at the Grand Prix Hassan II on Thursday in Marrakech, Morocco.

Griekspoor needed two hours and 23 minutes to dispatch Spaniard Pablo Carreno Busta 7-6 (1), 3-6, 6-3, hitting 13 aces along the way.

The Czech Republic's Vit Kopriva, meanwhile, saved 6 of 10 break points on his way to a 6-2, 5-7, 6-4 win over Sonego in two hours and 42 minutes. Kopriva had fewer winners than Sonego (24-21) but also fewer unforced errors (40-35).

Two other Italians fared better than Sonego on Thursday. No. 7 seed Luciano Darderi rallied past Frenchman Hugo Gaston 2-6, 6-2, 6-3, and No. 8 Mattia Bellucci beat French qualifier Pierre-Hugues Herbert 6-2, 7-5.

Tiriac Open

In a match postponed from Wednesday by rain, No. 1 seed Sebastian Baez of Argentina finished off Canada's Gabriel Diallo 7-6 (5), 2-6, 6-2 in Bucharest, Romania.

Diallo had a 4-1 edge in aces, but Baez saved 5 of 9 break points while converting 4 of 6 break-point opportunities.

No. 2 seed Pedro Martinez of Spain rallied past Swiss wild card Stan Wawrinka 4-6, 7-5, 6-2, and Bosnia and Herzegovina's Damir Dzumhur was a 6-4, 3-6, 6-3 winner over Romania's Filip Cristian Jianu.

Australian Christopher O'Connell toppled fourth seed Nicolas Jarry of Chile 6-2, 5-7, 7-6 (5) -- charging back from a 3-0 deficit in the third-set tiebreaker -- and Marton Fucsovics of Hungary beat No. 7 Mariano Navone of Argentina 4-6, 6-4, 6-4.

U.S. Men's Clay Court Championship

No. 4 seed Brandon Nakashima downed Mackenzie McDonald 6-1, 7-5 in an all-American affair in the Round of 16 in Houston.

Nakashima won 40 of his 49 total service points (81.6 percent) and advanced to face Christopher Eubanks, who won his first set 6-1 before Japanese eighth seed Kei Nishikori retired due to injury.

Two matches were slated for Friday evening: No. 2 seed Frances Tiafoe against Australia's Adam Walton, and No. 5 seed Alex Michelsen versus Frenchman Adrian Mannarino.

--Field Level Media