(CNN) -- They played in the U.S. Open final Monday but both Rafael Nadal and Novak Djokovic were back in action for their countries Friday.
They both won, too, overcoming fatigue, jet lag and a change of surface.
Nadal, who beat Djokovic in New York to claim his 13th grand slam title, prevailed 6-0 6-0 6-4 over Sergiy Stakhovsky -- Roger Federer's conqueror at Wimbledon -- on his favored clay.
He boosted his Davis Cup record in singles to a near invincible 21-1, with his lone reverse coming in his first outing against Jiri Novak in 2004.
Nadal hadn't played in the competition since 2011, opting to skip proceedings in 2012 even before his season was ruined by a knee injury.
"Today is another victory after a long year and every victory is important," Nadal told the Davis Cup website.
With Fernando Verdasco also winning his match in Madrid against Ukraine, it means Spain is on the verge of retaining its spot in next year's world group following an upset loss to Canada in February.
Nadal is scheduled for the potential doubles clincher Saturday alongside good pal Marc Lopez. If he does take to the court, it would be his first doubles tussle in the Davis Cup in seven years.
"To play with a good friend like Marc will be a special feeling, first time in the Davis Cup," said Nadal.
Canada kept on progressing in the Davis Cup and encountered Djokovic's Serbia in its maiden semifinal Friday.
But Djokovic was too strong in the opener versus big-serving Vasek Pospisil, cruising 6-2 6-0 6-4 on clay in Belgrade.
"I'm glad the match was short," the world No. 1 told reporters. "I forced him to make mistakes.
"I find additional inspiration playing for my country," added Djokovic, whose last loss in Davis Cup singles, not including a retirement, was against Nadal in 2009.
Canada, however, leveled the series when Milos Raonic toppled a slumping Janko Tipsarevic 5-7 6-3 3-6 6-3 10-8 in more than four hours.
Defending champion the Czech Republic moved closer to another final, leading Argentina 2-0 in their best-of-five contest in Prague. Argentina is playing without Juan Martin del Potro and Davis Cup standout David Nalbandian.
Great Britain, aiming to return to the world group for the first time since 2008, is tied 1-1 with Croatia in the playoffs.
After Wimbledon champion Andy Murray routed U.S. Open junior titlist Borna Coric on the road, Ivan Dodig defeated Dan Evans in Umag.
The only member of the 'Big Four' not to see action this weekend is Switzerland's Federer.
The Swiss, though, lead Ecuador 2-0 at home, in Neuchatel.