Zverev, 21, dug deep to hold off the big-serving Isner to win 3-6, 7-6 (8/6), 10-7. "I loved it. Obviously I wanted to win as much as Roger".
World number two Roger Federer says he is mulling a return to the European clay-court season in 2019 following a two-year absence.
Edmund then raced to a 7-2 lead in the 10-point tiebreaker that is used in the Laver Cup when the first two sets are split.
Though all the attention was on Djokovic and Federer, a third multiple major champion was on the court, too.
You might have heard of Bjorn Borg and John McEnroe, who have a combined 18 Grand Slam singles titles and a mountain of other tennis accolades.
Team Europe will now head into Day 2 with 3-1 lead after Grigor Dimitrov, Kyle Edmund and David Goffin pulled off singles win against Frances Tiafoe, Jack Sock and Diego Schwartzman respectively to make it 3-0 for Europe.
So far at the Laver Cup this week, it has just been a whole lot of photo opportunities-mostly of players in mismatched suits.
But rising German star Zverev showed great determination in saving a match point at 6-5 down in the second-set tie-break to level the contest.
Unlike a year ago, there was no joy for Federer.
Team Europe needs another six points to retain the title it won in the inaugural competition past year heading into Sunday's final day, when three points are on the line in each of the four matches.
Things were starting to look problematic for Team World after Kyrgios' defeat and John Isner's earlier to Zverev, but Anderson provided a timely tonic to swing some momentum.
Play resumes today with the tournament's final four matches worth three points apiece with everything to play for.
Each player will play at least one singles match during the first two days.