Russia's Daniil Medvedev missed out on a chance to return to the top of the world rankings as he lost to Poland's Hubert Hurkacz at the Miami Open.
Medvedev, 26, needed to reach the semi-finals to overtake Novak Djokovic, but lost 7-6 (9-7) 6-3 to eighth seed Hurkacz in Thursday's quarter-final.
Medevev trailed 5-2 in the first set, fought back to 5-5 but then lost the tie break 9-7.
Hurkacz, 25, then gained breaks in the fifth and ninth games of set two.
The Polish player, who beat Roger Federer in the quarter-finals at Wimbledon last summer, will now play either Spain's Carlos Alcaraz, the 14th seed, or Serbia's unseeded Miomir Kecmanovic.