Nadal and Djokovic were both expected back on court to play the decisive doubles rubber that will decide which country wins the 24-nation tournament.
"Every time I get to play Rafa we get to play a lot of exciting points. There were some incredible exchanges today," said Djokovic.
A battling Nick Kyrgios earned a morale-boosting victory over world number six Stefanos Tsitsipas on Tuesday, while Russia and Britain booked their spots in the ATP Cup quarter-finals.
Rafael Nadal suffered an upset singles loss but made amends in the doubles to keep Spain alive at the ATP Cup Friday, with Novak Djokovic also surviving a scare before rallying
Tennis’ innovative new team championship kicks off the men’s 2020 season on Friday, with Rafael Nadal and Novak Djokovic among those looking for a winning start ahead of the first