Czechs, Japan, Britain into Davis Cup last eight
Tomas Berdych of the Czech Republic celebrates after he defeated Thiemo de Bakker of the Netherlands 6-1, 6-4, 6-3 in their Davis Cup tennis match at the Cez Arena in Ostrava, Czech Republic, on February 2, 2014 - by Michal Cizek
Great Britain notched their first World Group win since 1986 as Andy Murray beat Sam Querrey in San Diego to give the Brits an unassailable 3-1 lead over the United States.
Britain next face Italy, who downed Argentina in Mar del Plata thanks to Fabio Fognini's third victory in as many days.
In Ostrava, the Czech Republic held the upper hand 2-1 going into the reverse singles against the Netherlands and Tomas Berdych bagged the all-important third point with a three-set win over lowly-ranked Thiemo de Bakker.
The Dutch claimed the final dead rubber when Igor Sijsling saw off Lukas Rosol giving the Czechs a 3-2 victory and a last eight date with Japan, who beat Canada in Tokyo.
There was an air of anti-climax about Japan's feat after Canada's Frank Dancevic retired injured from his rubber with Kei Nishikori.
Go Soeda thrashed Peter Polansky 6-1, 6-4 in the dead final rubber to complete a 4-1 rout over last year's semi-finalists.
"It's a bit hard being overjoyed to win like that but to make history is unbelievable," Nishikori, the world number 18, reflected.
The Czechs may have to travel to Tokyo without their star player, world number seven Berdych.
"I've won the salad bowl twice, I've given the team a lot over the past 10, 11 years. I'd say a rest would be fully deserved," he had warned earlier.
In California, where the United States hosted Britain on a clay court set up at Major League Baseball ground Petco Park, world number six Murray gained the crucial point with a 7-6 (7/5), 6-7 (3/7), 6-1, 6-3 win over Querrey -- the top US player in action after the late injury withdrawal of John Isner.
Querrey had been stunned on Friday by Britain's James Ward, who won 10 of the last 11 games in a remarkable five-set fight-back that helped the visitors take a 2-0 lead on the opening day on which Murray also crushed Davis Cup newcomer Donald Young.
After the crack doubles duo of Bob and Mike Bryan pulled back a point for the Americans on Saturday, Murray relished his chance to put the tie away.
"You want to try and contribute as much as possible in these weeks," Murray said. "James had a great win against Sam the first day to put us in that position and it was up to me today to try and close it out."
At Mar del Plata, Fognini beat Carlos Berlocq 7-76 (7/5), 4-6, 6-1, 6-4 to give Italy a 3-1 advantage that stood up after the dead rubber was scrapped.
Fognini had beaten Juan Monaco on Friday and teamed with Simone Bolelli for a doubles win over Horacio Zeballos and Eduardo Schwank on Saturday as Italy overcame the hostile crowd.
"I'm happy to be part of this team and that we can play another Davis Cup tie," Fognini said.
Serbia, trailing Switzerland 3-0, had only honour at stake in Novi Sad.
With the Swiss resting their top two players - Australian Open winner Stanislas Wawrinka and Roger Federer - last year's beaten finalists duly clinched the closing two academic rubbers courtesy of Filip Krajinovic and Dusan Lajovic.
The Swiss host Kazakhstan, who saw off Belgium 3-2 in Almaty, in the quarter-finals.
Germany, who held an unassailable 3-0 lead over five-time former winners Spain in Frankfurt, soured their win by claiming that three of their players were unfit to play.
That left the crowd and the Spanish short-changed, with the hosts unable to play the opening rubber of the day. Germany's last man standing, Daniel Brands, beat Roberto Bautista Agut in the fifth rubber to complete a 4-1 win.
Germany will want to put the bad taste left by the last-day no-shows behind them as they move on to face France, who completed a 5-0 whitewash of Australia on the clay courts of Mouilleron-le-Captif.
Gael Monfils and Julien Benneteau handed out three-set defeats to Aussie teenager Nick Kyrgios and Thanasi Kokkinakis respectively.
Richard Gasquet and Jo-Wilfried Tsonga, teaming up for the first time, had claimed the decisive point in Saturday's doubles against Chris Guccione and Lleyton Hewitt.
The quarter-finals of the 114-year-old competition are scheduled for April 4-6.