Rafael Nadal resisted the big heart and forehand of Juan Martin del Potro in a Wimbledon classic to set up what could be another match to savour in the semi-finals against Novak Djokovic.

The world number one should have led by two sets to love but was forced to come from behind before withstanding a supreme effort from his opponent in the fifth.

Eventually he clinched a 7-5 6-7 (7/9) 4-6 6-4 6-4 victory after four hours and 47 minutes.

Nadal, who is now two wins from an 18th grand slam title, held a commanding 6-3 lead in the second-set tie-break. It was a concern when that slipped away, in part through a double-fault error.

“Of course I was worried when I lost the second set,” Nadal said. “It’s true that he played two great points with his serve, but that double fault was a big mistake.

“Then the match changed. He played well. I believe I increased a little bit the level in the fourth and the fifth. But the fifth, he was playing huge. It was so difficult to stop him.

“I am very happy the way that I survived a lot of important points in that fifth set. I think I did a lot of things well. The only negative thing is I played almost five hours, and I had the chance maybe to play less winning that second set.

“For the rest of the things, great news, semi-finals of Wimbledon again. Great match, an emotional match for both of us and for the fans, too. Great feelings.”

The clash between Del Potro’s thunderous forehand and Nadal’s supreme defensive skills was a stalemate until the 12th game of the opening set, when the Spaniard pounced.

Juan Martin del Potro's forehand was in prime form
Juan Martin del Potro’s forehand was in prime form (Nigel French/PA)

Del Potro took advantage of a loose game from Nadal to serve for the set in the second only for the Spaniard to break back, and he looked sure to move two sets ahead when he opened up his big lead in the tie-break.

But Del Potro saved two set points on his own serve and then Nadal double-faulted. He had one more chance but again the Argentinian sent down a big serve and then, when his own chance came, Del Potro drilled a bullet forehand off the top of the net and onto the sideline.

The chink in Nadal’s armour was there again in the 10th game of the third set. Having cruised through his service games, he was broken to love serving to stay in it, Del Potro finishing it off with a scorching forehand down the line.

Both players were providing tremendous entertainment for the Centre Court fans, who had overwhelmingly chosen tennis over football, diving full length for shots, while Nadal chased one forehand so hard he ended up in the crowd.

The end looked nigh when Nadal broke for 3-2 in the decider but he tightened up and Del Potro kept hammering his forehand. Time and again the fifth seed threatened to get back on terms but five break points came and went and somehow Nadal held on.

Del Potro ended the match prostrate on the grass as Nadal held his arms aloft, before clambering over the net for a consoling, and exhausted, hug.

“I didn’t want to finish the match like that,” said Del Potro, who hit 77 winners. “After almost five hours, I fell down. I wanted to stay there for all night long. But Rafa came to me and we made a big hug, and it was kind of him.

“The crowd at the end was amazing. I think I played really good tennis today. But Rafa is Rafa. Sometimes you play your best tennis and it’s not enough to beat him. But I’m glad with my tournament. Physically I’m OK. That gives me confidence to keep going in the future.”