Two breaks in each set were enough for Nadal to seal an impressively comfortable victory over Zverev in what was only the 31-year-old's second outing since returning from a hip injury.
A prowling Nadal came up with 21 winners and world number four Zverev racked up 57 unforced errors as the 16-time grand slam champion extended his winning run to a Davis Cup-record 24 matches.
It was the 23rd straight win for Nadal since 2005, setting the Davis Cup record combining singles and doubles.
U.S. job growth slowed sharply in March
The March employment increase was led by monthly gains in the Public Administration (8,700) and Construction (6,700) sectors. The government counts people who are out of work as unemployed only if they're actively searching for jobs.
Ferrer and Kohlschreiber's match was locked at one set each at the Plaza de Toros in Valencia on Sunday. Germany then took a 2-1 lead when Tim Puetz and Jan-Lennard Struff won the doubles rubber against Feliciano and Marc Lopez.
Chardy, a surprise selection ahead of Adrian Mannarino, the world 25, suffered his first Davis Cup defeat in six matches.
Croatia will meet the United States in the semis in September.
Silver! Cyclists earn first Games medal for NZ
There was no sleep-in for the world record-holders in the Commonwealth Games pool on Friday. I think there is something to be said about a home-crowd advantage.
World number 11 Pouille, who had beaten Andreas Seppi in five sets on Friday, came from behind to see off Fognini 2-6, 6-1, 7-6 (7/3), 6-3 and send Yannick Noah's France into the semis for the third time in four years. "It was a great match for me in an unbelievable atmosphere".
World No. 1 Nadal had not played since he retired from his Australian Open quarterfinal against Marin Cilic in January with a leg injury, but made light work of Kohlschreiber to draw five-time victor Spain level at 1-1 in the tie.
In Nashville, John Isner and Sam Querrey lifted the Americans a 2-0 lead over last year's runners-up Belgium as the USA tries to reach the semis for the first time in six years.
Germany team captain Michael Kohlmann said: "This is what the Davis Cup is all about".
Masters 2018: Augusta National showing teeth early in Round 1
Spieth's Friday round is not televised or available for live streaming. "What a platform", Brennan said . "It's fabulous. Fred Ridley, now the chairman of Augusta National Golf Club, at the Green Jacket Ceremony past year .
The other two European match-ups are also 2-1 as it stands, as the France pair, boasting the ATP's No.9-ranked doubles player Nicolas Mahut alongside Pierre Hugues Herbert, raced to victory in straight sets, defeating Italy 6-4 6-3 6-1.