World No 1 Iga Swiatek outlasted Martina Trevisan to level Poland's United Cup city final on Wednesday after rising star Lorenzo Musetti produced an almost flawless display of serving to put Italy in front.
Musetti lost only three points on serve to beat Poland's Daniel Michalski 6-1, 6-1 in just 57 minutes in the best-of-five-match Brisbane city final.
The winners of the city finals in Brisbane, Sydney and Perth progress to the semifinals of the inaugural mixed teams tournament along with the best-performing losing finalist.
The 20-year-old Musetti, who climbed to 23 in the world in 2022, had far too much firepower for his opponent, blasting 17 winners past the 260th-ranked Michalski.
"I was so focused today on the match and the serve was really good," he said. "But with every shot I had a great feeling for the ball so I think I played the best match so far."
However, Poland struck back when Swiatek battled past Trevisan 6-2, 6-4.
The three-time Grand Slam winner raced through the first set but was forced into a fight in the second, finally claiming victory in 1hr 51mins.
"It became tight at the end and I felt like she had her chances as well," Swiatek said. "My goal is to be more consistent and keep the same level of tennis right to the end."
In Sydney, a tenacious Madison Keys gave the United States an early lead over Britain before Cameron Norrie struck back when he won a high quality match against Taylor Fritz in their city final.
World number 11 Keys lost the first set to Katie Swan before recovering to win a gruelling match 2-6, 6-3, 6-4 in 2hrs 18mins.
"I actually practised with Katie a few days before the tournament and I said to my coach she's playing absolutely great tennis," Keys said.
"So I knew I would have to play well and I think she played a phenomenal first set and I knew I had to raise my level."
Norrie and Fritz played an enthralling encounter which was in the balance until the Briton broke at 4-4 in the final set then served it out to claim a 6-4, 5-7, 6-4 victory.
"All credit to Taylor, we've played so many times and always had a battle so I was definitely ready for three sets," Norrie said.
Croatia took the first point in Perth when Donna Vekic downed Greece's Despina Papamichail 6-2, 6-0.
Stefanos Tsitsipas takes on Borna Coric in the second singles rubber.