Nadal would have expected to have to get past the third seed to reach the last four but Zverev’s underachievement at the grand slams went on as he was beaten in straight sets by Denis Shapovalov.
Nadal was up against veteran Frenchman Adrian Mannarino and the match was all-but decided in an epic first-set tie-break lasting nearly half an hour.
Mannarino had four set points before Nadal finally took it 16-14 on his seventh chance thanks to a net cord and wild volley from his opponent, and went on to claim a 7-6 (14) 6-2 6-2 victory.
The Spaniard said: “The first set has been very, very emotional, anything could happen there.
“I was a little bit lucky at the end. Everybody knows how mental is this game. After that crazy first set was so important that break at the start of the second. I’m very happy that I survived that first set without a doubt.”
It is starting to look like Nadal could be the big beneficiary of Novak Djokovic’s removal from the tournament but he will be wary of Shapovalov, who is through to his first quarter-final in Melbourne.
They have met four times before, with Shapovalov pulling off a stunning upset on home soil in Canada to announce his talent to the world aged 18.
“After the match I said he is going to be a potential multi-grand slam winner,” said Nadal.
“And I still think that, if he’s able to keep improving, he will be a multi-grand slam winner. He has a lot of amazing things in his game, and his results say that. When he’s playing well, it’s very difficult to stop him.”
Zverev certainly could not find the answers, smashing his racket and failing to serve out the second set in a 6-3 7-6 (5) 6-3 defeat.
The German, who finished 2021 on a high by winning the ATP Finals for the second time and had a chance to clinch the world number one spot this fortnight, offered no excuses about his performance.
“There is not much I can say or take away that was positive from today,” said Zverev. “Maybe since Wimbledon, one of the worst matches I have played. It’s just tough.
“Obviously I give credit to Denis. It’s incredible he’s in the quarters. I think he deserves it. He’s done a lot of work. He’s improved his game. But I’ve got to look at myself as well. Today was just awful from my side.
“I’ve got to do better. I came here with a goal to win, and maybe to become number one and all that. But, if I play like that, I don’t deserve it. It’s as simple as that.”
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