2023 Australian Open finalist Stefanos Tsitsipas, suffering from back pain, gave up playing the men's singles on Tuesday against Chile in the United Cup, then lost the mixed doubles, causing Greece's defeat.
Tsitsipas, world number 6, was to meet Chilean number one Nicolas Jarry (19th). His replacement Stefanos Sakellaridis, 416th in the world at 19, did better than resist, but ultimately lost 6-3, 3-6, 7-5 after saving 10 out of 12 break points.
In the women's singles, Maria Sakkari (8th) had previously outclassed Chilean Daniela Seguel 6-0, 6-1.
Tsitsipas returned to the court for the deciding mixed doubles with Sakkari, but they lost 6-7 (5/7), 6-3, 10-6 to Seguel and Marcelo Tomas Barrios Vera.
The United Cup, organized in Australia, is a national team competition where eighteen nations compete, divided into six groups of three before a knockout phase starting from the quarter-finals.