Poland won the United Cup title for the first time with victory over Switzerland, though they had to battle from behind after an opening singles defeat for world number two Iga Swiatek.
Former Olympic champion Belinda Bencic gave Switzerland the best possible start in Sydney with a 3-6 6-0 6-3 victory over Swiatek.
But Poland's Hubert Hurkacz came through a thrilling three-set encounter in the men's singles, levelling the tie with a 6-3 3-6 6-3 victory over three-time Grand Slam champion Stan Wawrinka.
In the deciding mixed doubles, Polish pairing Katarzyna Kawa and Jan Zielinski maintained their 100% record in the tournament, beating Bencic and Jakub Paul 6-4 6-3 to clinch a 2-1 victory.
"Finally we have made it - third-time lucky... I mean, not lucky because we worked really hard," said Swiatek about Poland's win, following defeats by Germany and the United States in the 2024 and 2025 finals.
"I want to thank our team because this year I felt like it was such a team effort. I really felt the support. Even though my singles performance wasn't perfect, you really got my spirits up and each of you believed to the end."
It looked as though Poland might lose a third consecutive final when Bencic continued her winning singles record at the United Cup with her ninth victory, beating Swiatek to give Switzerland the lead in their first final.
But Hurkacz wrestled Poland back into the tie, maintaining his own fine form after returning to competition following seven months out injured, beating 40-year-old Warwinka in his final season on the tour.
Then Kawa and Zielinski proved too strong for Bencic and Paul, showing the form that helped them win a deciding rubber against the American pairing of Coco Gauff and Christian Harrison in the semi-finals, as they claimed a fifth successive win in the tournament to clinch the title for Poland.