Hubert Hurkacz and Iga Swiatek clinched Poland's place atop Group B on Wednesday, defeating Czechia's Tomas Machac and Karolina Muchova 7-6(3), 6-3 to seal the critical tie 2-1 and a place in the quarterfinal of the United Cup. Czechia can still earn a spot in the quarterfinals by finishing as the best-placed second-placed country in Sydney.