British number one Cameron Norrie suffered a surprise defeat by Federico Coria in the Argentina Open.
The second seed received a bye into the second round and lost 6-2 4-6 6-3 to home hope and world number 106 Coria.
The defeat means Norrie, a finalist in Buenos Aires last year, will drop out of the world’s top 20 when the rankings are updated on Monday.
Norrie will hope to avoid falling further down the rankings when he tries to defend his Rio Open title next week.
Later on Thursday, Carlos Alcaraz, who Norrie beat in last year’s final in Brazil, reached the quarter-finals of the Argentina Open with a straight-set win against Camilo Ugo Carabelli.
Searching for his first title of 2024, the top seed and defending champion won 6-2 7-5 against the Argentine and will face Italian qualifier Andrea Vavassori in the next round.
Elsewhere, Australian Open champion Jannik Sinner swept past France’s Gael Monfils to reach the quarter-finals of the Rotterdam Open.
World number four Sinner, who playing in his first tournament since his triumph in Melbourne, won 6-3 3-6 6-3 to set up a last-eight encounter with Canada’s Milos Raonic.
