When play was suspended on Thursday, Zverev was two sets behind to one down on Court 1 but fought back to defeat the American youngster 6-4 5-7 6-7 6-1 6-2, in a match lasting over three hours.
Cibulkova did just that, regaining her composure to break and take the first set, before comfortably closing out victory in the second. "It makes me stronger mentally". Zverev broke and won four games in a row. "I don't think I did a good job of keeping in the moment and playing the person who was in front of me". "If I feel better, it might be two.' I thought I'd go out there and try".
On Monday, Gulbis will face No. 24 seed Kei Nishikori of Japan, who was the runner-up at the 2014 U.S. Open.
Having reached the round of 16, where he fell in 2017, Nadal will maintain at least a 50-point advantage in the ATP ranking over his main rival, Roger Federer of Switzerland, who is the defending champion and so will not add any points to his ranking from this year's tournament.
After enjoying the best Grand Slam run of his career when he made the French Open quarter-finals last month, Zverev is hoping to reach the last eight at Wimbledon for the first time.
But then came one injury after another and a slide to 589th a year ago because of a lack of matches. "He's obviously had good wins through these last three matches here".
Like Zverev, the 20-year-old Fritz is a former junior world No. 1 earmarked for great things but yet to truly arrive at the highest level. He said: "I'm proud of qualifying here, of winning three five set matches, and this match in particular because I was two sets down".
"Stopping yesterday two sets to one down was not a nice feeling, but I came out today and knew I would have chances", Zverev said. There was no going back there for me.
On Friday, Alexander Zverev had to overcome some doubts both on and off the court.
The Wimbledon tennis tournament is well-known for its strawberries and cream.
Ernests Gulbis of Latvia celebrates defeating Alexander Zverev of Germany in their men's singles match on the sixth day at the Wimbledon Tennis Championships in London, Saturday July 7, 2018.
Zverev's tournament almost ended before it got started when in his second round match against American Taylor Fritz, though.