Defending champion Daniil Medvedev reached the semi-finals of the Dubai Free Tennis Championships with a 6-2, 6-3 win over Alejandro Davidovich Fokina.
The World No. 4 will face either Hubert Hurkacz or Ugo Humbert in the last-four.
Elsewhere, second seed Andrey Rublev advanced to the semi-finals when American Sebastian Korda retired with injury.
Rublev was leading 6-4, 4-3 when Korda pulled out.
The World No. 5 Russian will play Kazakhstan's Alexander Bublik, whose opponent Jiri Lehecka retired on Thursday.
Bublik, seeded seventh, led 6-4, 4-1 when Lehecka withdrew from the the quarter-final match.