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.
Spaun caps rainy US Open with monster putt for first major title
Paris Saint-Germain rolls past Atletico Madrid in CWC play
Russell wins in Canada as McLarens collide
Maria crowned first Queen's Club women's champion in 52 years
Messi falls just short in Club World Cup curtain-raiser stalemate
