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.