No. 1 seed Tommy Paul defeated qualifier Colton Smith 6-1, 7-6 (1) in the quarterfinals of the US Men's Clay Court Championship on Friday in Houston.

In a matchup of the 13th and 200th-ranked players in the world, Paul dominated on his serve, winning 22 of 24 first-service points (91.7 percent) and 41 of 51 service points overall (80.4 percent). Paul had a 23-13 edge in total winners and capitalized on Smith's 31 unforced errors.

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Paul's next opponent will be qualifier Jenson Brooksby, who came back to beat Aleksandar Kovacevic 2-6, 6-3, 6-4. No. 4 seed Brandon Nakashima was a 6-4, 6-4 winner over Christopher Eubanks.

All eight players still standing at the start of Friday were American. The last match of the night, between No. 2 seed Frances Tiafoe and No. 5 seed Alex Michelsen, was suspended due to rain but was expected to be played.

Grand Prix Hassan II

Dutch No. 1 seed Tallon Griekspoor hit five aces and went 4-for-4 saving break points to cruise past Italian eighth seed Mattia Bellucci 6-3, 6-4 in the quarterfinals in Marrakech, Morocco.

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No. 3 seed Alexandre Muller of France wasn't as fortunate, as Polish qualifier Kamil Majchrzak cleaned up with a 7-5, 6-4 win in an hour and 36 minutes. Griekspoor and Majchrzak will square off in the semis.

Meanwhile, No. 5 seed Roberto Carballes Baena of Spain edged fourth seed Nuno Borges of Portugal 6-4, 6-4, and seventh seed Luciano Darderi of Italy beat Czech opponent Vit Kopriva 7-5, 6-2.

Tiriac Open

No. 1 Sebastian Baez survived a tough three-set encounter against Argentine countryman Francisco Comesana, prevailing 7-6 (5), 2-6, 6-1 in Bucharest, Romania.

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Baez saved 7 of 10 break points while breaking Comesana on 4 of 7 opportunities. In the semifinals, he'll face Hungary's Marton Fucsovics, who beat Australia's Christopher O'Connell 6-0, 6-4.

Damir Dzumhur of Bosnia and Herzegovina continued a surprise run into the semifinals by advancing past No. 2 seed Pedro Martinez Portero of Spain. Dzumhur led 6-1, 2-0 when Martinez Portero retired due to injury. He'll face No. 3 Flavio Cobolli of Italy, who beat Austrian qualifier Filip Misolic 7-6 (5), 6-4.