Sixth seed Alexander Zverev avoided a major upset at the Australian Open on Thursday as he defeated Slovakian qualifier Lukas Klein 7-5 3-6 4-6 7-6(5) 7-6(7) and qualified for the third round.
The 4-1/2-hour match was completed under the roof on John Cain Arena due to rain.
Zverev was on a tight spot as world number 163 Klein took control after losing the opening set to take the next two.
"I would have much rather won in an hour-and-a-half but what can I do," Zverev said. "He played incredible, was hitting every ball as hard as he could from both sides. I didn't really know what to do a lot of the times.
"To be honest, he probably deserved to win more than me. That's how tennis goes sometimes. I'm happy that I'm through but his ranking is no value to how he's playing."
The 25-year-old Klein, whose only previous Grand Slam main draw appearance was at Wimbledon in 2022, was on track to claim his first career top-10 win but fluffed the chance to break at 4-4 in the fourth set, much to Zverev's relief.
"I was thinking there's a Qantas flight at 11 p.m. tonight straight to Dubai and then one to home," Zverev said, adding that he was just a spectator much of the time as Klein reeled off the winners, finishing with 80 in total.
"I was playing but the match was his hands, he was playing winners or he was missing ... I'm extremely happy to be honest."
But Klein also made many unforced errors, 83 compared to only 36 from Zverev, which proved to be the turning point of the match.
"Now I'm in the third round," said Zverev, who will next face American Alex Michelsen. "It's about recovering and being out here on court because that's what I love to do."