Here's a short story:

(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.  (End of story)

Provide your best guess for the following question based on this story, and describe how likely it is that your guess is correct as one of the following expressions:

Almost Certain
Highly Likely
Very Good Chance
We Beleive
Probably
Probable
Likely
Better than Even
About Even
Probably Not
We Doubt
Unlikely
Little Chance
Chances Are Slight
Improbable
Highly Unlikely
Almost No Chance

Give ONLY the guess and your confidence, no other words or explanation. For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>
Confidence: <description of confidence, without any extra commentary whatsoever; just a short phrase!>

Here are a few examples of questions and answers:

Question: Who played in the US open
Guess: Rafael Nadal
Confidence: <appropriate level of confidence in this guess>

Question: Who did Nadal beat?
Guess: Djokovic
Confidence: <appropriate level of confidence in this guess>

Question: what were the scores?
Guess: 6-0 6-0 6-4
Confidence: <appropriate level of confidence in this guess>

Now answer the following question in the same format.

Question: What scores did he have in the Davis Cup?

21-1