The 2-0 leads for the Czechs over host Belgium, Serbia over the United States, France against Germany, Russia over India, and Croatia against Ecuador followed the formbook, but Argentina surprisingly tied Sweden 1-1 in Stockholm and gave David Nalbandian another chance to be a hero.
Chile and Israel were set to start their tie in Coquimbo on Saturday, a day late because of the killer earthquake and tsunami last weekend.
In a converted Logrono bullring, Swiss No. 1 Stanislas Wawrinka, playing his first match since the Australian Open after the birth of his daughter, outlasted Nicolas Almagro 3-6, 6-4, 3-6, 7-5, 6-3, but David Ferrer accounted for Marco Chiudinelli 6-2, 7-6 (5), 6-1 to soothe Spanish worries.
How far Switzerland push Spain will depend on Wawrinka, who after playing four hours on Friday will have doubles on Saturday and reverse singles on Sunday, a day the tie wasn't expected to be alive. Next, though, he and Yves Allegro will meet the experienced Tommy Robredo and Marcel Granollers, who have teamed up for the first time in the cup.
In Bree, Tomas Berdych and Radek Stepanek began their quest to return the Czech Republic to the final for a second straight year by not dropping a set against Belgium.
Berdych defeated Olivier Rochus 6-3, 6-0, 6-4 despite 36 unforced errors then Stepanek downed Xavier Malisse 6-2, 6-4, 7-6 (3). The pair wasn't named for the doubles but with an opportunity to clinch the tie and advance to the quarterfinals on Saturday, Berdych and Stepanek could be back on court. They won their first five cup matches together until losing to Spain in last year's final. Belgium named Steve Darcis and Rochus, who have teamed up only once before in the cup.
In Toulon, former top-10 player Gael Monfils earned his first cup win by beating Philipp Kohlschreiber 6-1, 6-4, 7-6 (5), while Jo-Wilfried Tsonga remained unbeaten since his cup debut in 2008 when he defeated Benjamin Becker 6-3, 6-2, 6-7 (2), 6-3 for France to put Germany in a 2-0 hole.
Germany hasn't overcome a 2-0 deficit in 50 years, nor beaten France in 72 years.
"Tonight I'm a relieved and happy captain," France's Guy Forget said. "But we are still needing a point. We are not going to be carried away before we'll score the third point. I wouldn't mind if it was tomorrow after the doubles."
When Nikolay Davydenko's replacement Igor Andreev hurt his knee in practice, Igor Kunitsyn received only an hour's notice that he was playing, and duly beat Somdev Devvarman 6-7 (6), 7-6 (4), 6-3, 6-4 to set Russia rolling against India, making its first World Group appearance since 1998.
"I came to cheer for my teammates," Kunitsyn said. "There's no way you can prepare yourself for a match in one hour. The pressure was huge on me. It all was for the first time _ first live singles match, first time at home."
Mikhail Youzhny capped another good day for the home team in Moscow by dispatching Rohan Bopanna 6-4, 6-2, 6-3. Russia hasn't lost at home since 1996.
In Varazdin, Croatia managed to handle the Lapentti brothers.
Ivo Karlovic overcame Nicolas Lapentti 6-2, 5-7, 6-7 (2), 6-3, 6-4, then new top-10 player Marin Cilic downed Giovanni Lapentti 6-4, 6-3, 6-3.
Nicolas Lapentti reversed his decision last year to retire, and withstood 36 aces from Karlovic to almost pull off a stunner.
In Belgrade, Viktor Troicki beat John Isner in his cup debut 7-6 (4), 6-7 (5), 7-5, 6-4, then Novak Djokovic saw off Sam Querrey 6-2, 7-6 (4), 2-6, 6-3 to put Serbia in command against the United States.
Djokovic, the only top-six player in action, was frustrated by Querrey and made 54 unforced errors, but experience prevailed as Serbia eyed its first quarterfinal.
"Despite our big 2-0 lead, nothing is decided yet," he said. Serbia will pit doubles world No. 1 Nenad Zimonjic and Janko Tipsarevic against America's impressive Bryan twins.
In Stockholm, Leonardo Mayer rallied to beat Joachim Johansson 5-7, 6-3, 7-5, 6-4 in his first cup singles after Robin Soderling beat cup debutant Eduardo Schwank 6-1, 7-6 (0), 7-5 to leave Argentina tied with Sweden and a chance for Nalbandian to shine.
Nalbandian, who has led Argentina to two finals in the last four years, was back from injury sooner than expected, and could line up in the doubles to try and keep surprising the Swedes.