Juvan, ranked 104 in the world, crushed 814-ranked Danilina 6-1, 6-0 in 53 minutes.
Teammate Tamara Zidansek won the first set of the second rubber against Yulia Putintseva to ensure Slovenia finished top of Group B and join Italy and Canada in the semi-finals of the women's team event.
Zidansek retired after the second set with Putintseva as a result winning 2-6, 6-2, which was enough for Slovenia to seal their place in the last four.
The Slovenians will meet Italy on Saturday, after the Italians secured their berth on Thursday by finishing first in Group D.
The other semi-final will see Canada, also qualified since Thursday, face either the United States or the Czech Republic, who will battle for top spot in Group A later Friday.
In group D, the clash for honour between eliminated France and Germany favoured the French.
Clara Burel put France on the right track by beating Julie Niemeier 6-4, 6-3.
Then newcomer Varvara Gracheva won the second singles rubber after German rival Tatjana Maria withdrew while leading 3-0.
Each BJK Cup match consists of two singles followed by a doubles. Each group four group winners advances to the semi-finals.
The 2022 edition was won by Switzerland, who beat Australia, but both nations were eliminated in the group stage this year.
