Slovenia beat seven-time winners Australia in the Billie Jean King Cup finals opener on Tuesday in Seville, taking a 2-0 lead in the best-of-three tie.
Kaja Juvan and Tamara Zidansek won their singles rubbers against last year's runners-up to get Slovenia off to a strong start on their finals debut before the closing doubles.
Juvan defeated Ajla Tomljanovic 6-4, 6-1 before Zidansek beat Daria Saville 6-1, 6-4.
Juvan got the ball rolling with a comfortable straight-sets win over Tomljanovic.
The Slovenian served strongly, winning 72 per cent of her first serve against her tiring Australian opponent, who has endured an injury-hit season, playing just five matches prior.
Juvan has a strong record at the Billie Jean King Cup, recording her 10th victory in 11 matches across singles and doubles.
"I feel really good playing here and I was thinking today, I can't seem to lose at this (competition)," said Juvan.
Zidansek produced seven aces against Saville as Slovenia moved top of Group B, which also features a solid Kazakhstan team.
"I'm really happy with the way I played, at the beginning I was looking for my rhythm," said Zidansek.
"It's special, we don't (often) get that in tennis because it's an individual sport."
Later Tuesday defending champions Switzerland face the Czech Republic in a Group A heavyweight clash.