Lucie Safarova had two wins - one in the women's singles, another in the mixed doubles - to give the Czech Republic a 2-1 victory over Canada on the opening day of the Hopman Cup on Sunday.
Safarova defeated Wimbledon runner-up Eugenie Bouchard 6-0, 6-4 to give the Czechs an early 1-0 lead, then teamed with Adam Pavlasek to beat Bouchard and Vasek Pospisil 6-4, 6-2 in the mixed doubles decider.
In between, Pospisil secured the Canadians' only point with a 7-6 (5), 6-2 win over Pavlasek in the men's singles.
Seventh-ranked Bouchard, coming off a breakthrough season that saw her reach the final at Wimbledon and two other Grand Slam semifinals, was no match for the No. 16-ranked Safarova in the tournament opener at Perth.
"I was going for all my shots, and it worked well," Safarova said. "I tried to keep the pressure on, quickly. When she has time, she takes control."
In the night session Sunday, Poland took a winning 2-0 lead over Australia after the singles matches. Agnieszka Radwanska beat Casey Dellacqua 6-2, 6-3 and Jerzy Janowicz defeated Matt Ebden 3-6, 7-5, 6-0, with Ebden double-faulting on match point.
On Monday, Serena Williams was set to play her first match for the United States with John Isner against Italy, while Andy Murray leads Britain against France.
Williams said the high temperature of 41 degrees Celsius (106 Fahrenheit) forecast for Monday would suit her just fine as preparation for the frequently scorching conditions at the Australian Open in two weeks.
"If anything it's going to help me for Melbourne," Williams said Sunday. "Perth is one of the hottest places I've ever played, so it will be really good for the preparation in Melbourne, which is always super-hot."
The Perth Arena roof will be shut during Williams' match against Italian Flavia Pennetta if the heat policy is enforced, or both players agree the conditions are unsafe.
At the Brisbane International, another of the Australian Open warm-up events ahead of the Jan. 19 start of the first Grand Slam of the year, hometown hope and former U.S. Open champion Samantha Stosur lost her first-round match 4-6, 6-4, 7-5 to Varvara Lepchenko of the United States on an opening day of upsets.
Earlier, Ajla Tomljanovic beat sixth-seeded and former No. 1 Jelena Jankovic of Serbia 7-6 (6), 6-0.
Tomljanovic, who was born in Croatia but is now based in Brisbane, is planning to apply for Australian citizenship in the next few months.
In other matches, seventh-seeded Carla Suarez Navarro of Spain beat Tsvetana Pironkova of Bulgaria 3-6, 6-2, 6-1 and Kaia Kanepi of Estonia upset fifth-seeded Andrea Petkovic of Germany 6-4, 5-7, 6-4.
Maria Sharapova is the top-seeded player in the women's tournament, while Roger Federer headlines the field in the men's draw, alongside defending champion Lleyton Hewitt.