The US have taken a 2-0 lead over the Czech Republic on day one of the United Cup courtesy of wins by Taylor Fritz and Madison Keys.
World No.9 Fritz had an impressive 6-3 6-4 victory over Jiri Lehecka to get the mixed teams competition under way in Sydney.
Keys then accounted for Marie Bouzkova 6-4 6-3 to give the United States a perfect start.
Keys showcased her world No.11 status by winning the big points. The 2017 US Open finalist broke Bouzkova in the 10th game of the first set and the eighth game of the second, and held her next service games on both occasions.
The win continued the 27-year-old's love affair with Australia; Keys' semi-final finish at the most recent Australian Open was her best result at a grand slam since 2018 and followed her triumph at the 2022 Adelaide International.
"I love playing here," Keys said.
"Whether it's the people or that I like playing in the heat at the start of the year, it's fast and bouncy, it suits my game really well."
Fritz also came to the fore when under pressure.
Lehecka had break points in Fritz's opening two service games in the second set but the American nailed his first ball each time to keep the Czech at bay.
The set stayed on serve until the ninth game when Fritz took his opportunity, serving it out in style with an ace on match point.
"Hopefully there are a lot more wins this week," he said.
"It's good to start out 2-0 on the day as well for the team. We're all here to try and win it so it's a great way to start."
Fritz made his way into the top 10 in October for the first time in his career in a year where he turned in his best performances in grand slams. He reached the fourth round of the Australian Open and quarter-finals at Wimbledon.
The 25-year-old had a superb 6-3 7-6 win over Rafael Nadal at this year's Indian Wells Masters to confirm his upward trajectory.
Meanwhile, the Italy-Brazil tie in Brisbane is evenly poised at 1-1 after rising star Lorenzo Musetti beat Felipe Melegeni Alves 6-3 6-4.
World No.15 Beatriz Haddad Maia had got Brazil off to a fast start with a 6-2 6-0 thrashing of Martina Trevisan before 20-year-old Musetti hit back for the Europeans.
