The Czech Republic took a 2-0 lead on home soil in the Fed Cup final against defending champions United States.
Barbora Strycova and Katerina Siniakova both won their matches against Sofia Kenin and Alison Riske respectively to put the hosts one point from victory.
Strycova, playing in the last Fed Cup tie, went a set down in Prague to Kenin but won 6-7 (5-7) 6-1 6-4.
Siniakova had a more straightforward victory as she beat Riske by 6-3 7-6 (7-2).
Two singles matches and a doubles contest are scheduled to take place on Sunday, with the Czech Republic trying to secure a sixth Fed Cup title in eight years.
The inexperienced USA team are without Serena and Venus Williams as well as Sloane Stephens and Madison Keys, while the hosts have Karolina Pliskova injured.
Petra Kvitova was also out for the Czech Republic because of an illness but could play on Sunday.