Top-seed Daniil Medvedev was stunned by Tallon Griekspoor at the Dubai Tennis Championship on Thursday as the world number 47 recorded the biggest win of his career.
The Dutchman saved three match points to win through 2-6, 7-6, 7-5 to reach the semi-finals at the ATP 500, his eighth last-four appearance on the ATP Tour.
Griekspoor had already beaten Roman Safiullin in the first round and defending champion Ugo Humbert in the second, and will now face fourth seed Stefanos Tsitsipas, who won a hard-fought match 7-6, 1-6, 6-4 against Matteo Berrettini to reach his first semi-final since July 2024.
Quentin Halys, who beat Roberto Bautista, will play Felix Auger-Aliassime in the other semi-final after he defeated Marin Cilic.
In the Mexican Open, world number two Alexander Zverev was dumped out after straight-set defeat by teenage qualifier Learner Tien.
Zverev was the top seed in Acapulco after reaching the Australian Open final, but committed numerous errors against the American who won 6-3 6-4.
The 19-year-old, who will face Czech Tomas Machac in the quarter-finals, had beaten Cameron Norrie in the previous round.
Zverev becomes one of six seeds to exit the competition in the second round.
In the Merida Open, the British number five Fran Jones is out after she retired during the third set of her round of 16 match against Emiliana Arango.
Jones won the first set 6-3 before losing the second by the same score, but withdraw despite leading 4-3 in the final set.
