Top seed Daniil Medvedev, after a battle in the second round, had a smoother outing Thursday in defeating Alejandro Davidovich Fokina 6-2, 6-3 in the quarterfinals of the Dubai Duty Free Tennis Championships. Medvedev had needed three sets to oust Italian Lorenzo Sonego a day earlier, but the Russian rode 15 winners, three aces and just six unforced errors to dispatch Spain’s Davidovich Fokina in one hour and 17 minutes.

Fifth seed Ugo Humbert of France outlasted No. 3 Hubert Hurkacz of Poland, 3-6, 7-6 (8), 6-3 to advance to the semifinals against Medvedev. Humbert saved three match points in the second-set tiebreak. He hit 24 winners in the match lasting two hours and 24 minutes.

Two other seeded players advanced when their unseeded opponents retired due to injury during their quarterfinal matches. No. 2 Andrey Rublev of Russia eliminated American Sebastian Korda 6-4, 4-3 (retired), and No. 7 Alexander Bublik of Kazakhstan moved past the Czech Republic’s Jiri Lehecka 6-4, 4-1 (retired).

Fourth-seeded Alejandro Tabilo won an all-Chilean second-round matchup in Santiago, Chile, beating Tomas Barrios Vera 6-2, 7-5. Tabilo won 91 percent of his first-serve points and did not face a break point. Tabilo advances to a quarterfinal match against Italy’s Luciano Darderi, who downed Argentine qualifier Juan Manuel Cerundolo 6-3, 3-6, 6-3.

Second-seeded Sebastian Baez of Argentina rallied past Peru’s Juan Pablo Varillas 4-6, 6-4, 6-2. Baez’s quarterfinal foe will be eighth-seeded Jaume Munar, who routed Spanish countryman Albert Ramos-Vinolas 6-3, 6-1.

In the other quarterfinals, third-seeded Arthur Fils of France will face Spain’s Pedro Martinez, and top-seeded Nicolas Jarry of Chile will go up against French qualifier Corentin Moutet.