Petra Kvitova and Karolina Pliskova both recorded singles victories as Czech Republic finished day one of their Fed Cup semi-final with Germany 2-0 ahead.
Both Czech players recorded straight-set victories on the indoor clay surface, and the 10-time champions know one more point will see them progress to the final.
Defending champions United States are level with France in the other tie, Kristina Mladenovic making it 1-1 after Sloane Stephens had overcome Pauline Parmentier in a see-saw opening battle.
Meanwhile, there were a host of big names involved in the play-offs further down the competition.
Simona Halep, Garbine Muguruza and Jelena Ostapenko all came through without any problems, but only the latter claimed a straight-sets victory.
PETRA LEADS THE WAY
Kvitova found herself 3-1 down in the opening set with Julia Goerges, but the world number 10 rattled off five in-a-row to move ahead in the match.
She did not look back from there as she completed a 6-3 6-2 victory, the second set taking just 28 minutes.
Pliskova followed suit against former world number one Angelique Kerber as the Czechs – who have won five of the last six editions of the competition – took control ahead of the doubles on Sunday.
HONOURS EVEN IN FRANCE
Stephens beat Parmentier 7-6 (7-3) 7-5 but it was a tough opener for the holders in front of a raucous home crowd that included former world No 1 Amelie Mauresmo.
Parmentier raced out to a 5-2 lead in the opener but failed to take five set-point opportunities, allowing her opponent to rally before taking the lead courtesy of a tie-break.
Stephens was pushed hard in the second set too, fighting back from a break down to clinch victory with a crunching forehand winner in the 12th game.
However, team-mate Coco Vandeweghe blew a one-set lead against Mladenovic, who snapped her opponent's 13-rubber winning streak in the competition with an impressive 1-6 6-3 6-2 triumph.
HALEP SURVIVES SCARE
The pressure was on world number one Simona Halep as she opened up for Romania, and she survived a scare to ease past Switzerland's Viktorija Golubic 6-3 1-6 6-1.
Halep was broken in the first game of the match and lost five in a row in the second set, but she dug deep to give Romania a 1-0 advantage, with Irina-Camelia Begu putting them in the driving seat for a World Group place next year with victory over Timea Bacsinszky.
In the World Group II play-offs, French Open champion Jelena Ostapenko beat Ekaterina Makarova as Latvia finished day one against Russia 1-1, while Spain – led by Garbine Muguruza – hold a 2-0 lead over Paraguay.