The Spaniard will now continue his pursuit of a 15th grand slam title against either sixth seed Gael Monfils or Germany's world number 33 Philipp Kohlschreiber.

When the final point was won, Nadal thrashed his arms in delight as the 30-year-old moved into the last 16 of a grand slam for only the second time in six attempts.

More than just his progress, however, this victory could do wonders for confidence given Nadal, back from another injury lay-off, had lost his last three five-setters at major tournaments.

Zverev showed here why he is considered a multiple grand slam winner of the future but the 19-year-old looked to be struggling with cramp at the end, as Nadal twice came from a set down to go through.

Asked how he won, Nadal said: "By fighting. And by running a lot. I think everybody knows how good Alexander now is.

"He is the future of our sport and the present too. It was a tough match for me, I was not playing my best and not feeling well because I was losing too much court.

"Then I changed the dynamic in the third, I was feeling better (and) I had more time to control the points from the baseline.

"After losing the tie-break, I said, 'I need to fight for every point. Forget the result'. And that's what I did."

One break was enough to settle each of the opening two sets but Zverev showed nerves of steel in the third, pulling 6-5 ahead in the tie-break before driving home a backhand winner.

The youngster thrashed his hands with his chest facing the sky but Nadal was not done yet.

He stormed 3-0 clear in the fourth and then served out, leaping up to finish a backhand smash and then jumping a second time, this time to punch the air in celebration.

The Spaniard broke again at the start of the decider but Zverev hit back, opening up 0-40 at 2-1. He missed the first chance by framing a forehand into the crowd, and then a second, but grabbed the third when Nadal sent an anxious forehand long.

At 2-2, a scintillating game, lasting nine minutes, ensued. A wide Zverev backhand gave Nadal break point but the Spaniard's pass hit the net. Nadal had a second break point but this time Zverev unleashed a backhand winner cross-court.

And then at deuce, Nadal chased down a Zverev volley and whipped it down the line. This time he won the break as a Zverev forehand landed long.

Zverev hobbled into the changeover, mentally shot and perhaps physically worn down, as the physio enveloped his left thigh in spray.

Nadal held for 4-2 and, with his opponent on the ropes, went for the kill.

He sent one forehand left, one forehand right before driving a winner into the gap. He guided a backhand lob over Zverev's head and then cracked a forehand down the line. He chased down Zverev's drop-shot and patted it away for a winner.

One more rasping forehand and he had the second break, victory within his grasp. All that was left was for Nadal to serve out and when a tired Zverev forehand hit the net, his match was finally won.