Petra Kvitova and Lucie Safarova handed holders Czech Republic a 2-0 lead over Australia after the first day of their Fed Cup World Group tie in the eastern Czech city of Ostrava on Saturday.
In the first rubber, Kvitova, the Czech number one and world number eight, beat Australia's 168-ranked Jarmila Gajdosova 7-6 (7/2), 6-3 in an hour and 35 minutes.
Safarova, the world number 18, then snatched two tie-breaks for a 7-6 (8/6), 7-6 (7/4) win over ninth-ranked Samantha Stosur in two hours and 28 minutes.
Kvitova, the 2011 Wimbledon champion who led the Czechs to Fed Cup victories in 2011 and 2012, struggled for composure in the first set before dominating the second.
"It wasn't an easy match and she had moments when she played very well, but she also helped me a few times," the 22-year-old Kvitova said.
"I was terribly nervous in the first set."
Gajdosova, who has sunk from a career-high ranking of 25 in the past two seasons, said she had played a "pretty decent match."
"I had a lot of chances in the first and second set. Unfortunately I didn't take them," said the 25-year-old Gajdosova, who was born in Slovakia which formed a single country with the Czech Republic until 1993.
On the hard surface in Ostrava, about 320 kilometres (200 miles) east of Prague, Safarova then battled Stosur in a tight game, with each giving up five breaks.
On Sunday, Kvitova will first face Stosur. If she gives the Czechs a winning 3-0 lead, the tie will go straight to doubles, while if she loses, Safarova will take on Gajdosova.
In the doubles, Czechs Andrea Hlavackova and Lucie Hradecka, the world numbers three and four in the format, will face Australian Open finalists Casey Dellacqua (21 in doubles) and 16-year-old Ashleigh Barty (46).
The Czech Republic and former Czechoslovakia have won seven Fed Cup trophies together, just like Australia whose last success was back in 1974.
This puts both teams second in the historic Fed Cup rankings behind the US with 17 trophies.