Defending champions the Czech Republic, bidding to become the first country in 18 years to capture three successive Fed Cup titles, opened a 2-0 lead over Australia in their first round clash on Saturday.
Petra Kvitova gave the holders a convincing start in the eastern Czech city of Ostrava when the world number eight beat Australia's 168-ranked Jarmila Gajdosova 7-6 (7/2), 6-3.
Lucie 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.
The other three World Group One ties were level after the first day.
Italy and the United States, Russia against Japan and the tie between Serbia and Slovakia were all heading for a dramatic conclusion on Sunday with two reverse singles and a doubles to play.
Kvitova, the 2011 Wimbledon champion, who led the Czechs to victory 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," said the 22-year-old.
Safarova then battled Stosur in a tight match, with each woman giving up five breaks.
"It was very hard, the matches with her are always tight. But I handled it very well," said the 26-year-old Safarova.
Stosur, 28, failed to convert five set points in the first set and then gave up a break as she served for the second set.
"Unfortunately for me, I guess she got all those important points to get it back even and then kick on and get each set," said the 2011 US Open champion.
Seventeen-time champions United States battled back on the Rimini clay courts against Italy, the 2006, 2009 and 2010 champions, to stand 1-1.
Italy had defeated the USA in the 2009 and 2010 finals and looked on course for another comfortable win when Sara Errani outclassed Jamie Hampton 6-2, 6-1.
But Varvara Lepchenko, the Americans' top player in the absence of Serena Williams and Sloane Stephens, marked her debut with a come-from-behind 2-6, 6-4, 7-5 win over Roberta Vinci.
In Moscow, Ayumi Morita drew Japan level 1-1 against Russia by dismantling Ekaterina Makarova 6-2, 6-2.
Earlier, Maria Kirilenko, Russia's leading player after Maria Sharapova was not selected, put the home team in front with a 7-6 (7/3), 6-4 win over 42-year-old Kimiko Date-Krumm.
"Katya (Makarova) is a very strong player, who is in the world's top 20, and I needed to perform my best tennis against her to win," said Morita.
In Nis, Serbia, last year's runners-up, and Slovakia were locked at 1-1 but the visitors suffered a heartbreaking end to the day when Dominika Cibulkova was serving for the match against Vesna Dolonc.
Cibulkova was 6-4, 5-4 ahead but had to concede the match after suffering cramps.
"The cramps started in her right calf muscle and although we gave her magnesium the pain soon spread to the rest of the body," said Slovakia team captain Matej Liptak.
"These things can happen and I feel really sorry for Dominika, but more importantly the first priority for us is that she recovers fully. We can't say now whether she will be fit to play on Sunday."
Daniela Hantuchova had earlier seen off Bojana Jovanovski 7-5, 6-2 to give Slovakia a 1-0 lead.