Rune went 2-0 up in the third, but Zverev fought back, and there was all to play for at 4-4.

Rune broke again, to take the set 7-5.

Rune might have won the first, but number four seed Zverev dominated the second.

The Norwegian managed to win just one game in the second set, in a match that threatens to finish late in the evening, just two days after Djokovic finished at 3am.

Zverev lost the first set against Rune in the evening match on Philippe Chatrier in the fourth round.

The duo are fighting it out for a place in the quarter-final.

Novak Djokovic limped into the quarter-finals of the French Open after defying a knee injury to come through the longest Roland Garros match of his career.

The defending champion defeated Francisco Cerundolo – in another five-setter – 6-1 5-7 3-6 7-5 6-3 in four hours and 39 minutes.

World number one Djokovic blamed the slippery court for the injury he appeared to sustain at the start of the second set.

Djokovic: “I want to say a big thank you because once again like the last match the win is for you and helped by you because the last match I was two sets to one down, and at the fourth set 2-2 you gave me so much energy, so really thank you, what can I say, I was maybe four points away from losing this match but Fransisco played with so much quality, well done.

“He deserves this applause that’s for sure, the words after winning today, I don’t know, but thank you for the support.”

Djokovic takes one step closer to winning the match with a Cerundolo return that bounces out. His second return hits the net, and the world number one is just two points away from another quarter-final.

This time Cerundolo is equal to Djokovic’s drop shot, carves out his opportunity and plays a passing shot to make it 30-15.

A backhand return goes into the net, Djokovic is just one point away. He uses his hands to get the crowd on their feet and behind him.

Djokovic wins the match after four hours and 39 minutes!

Djokovic could win the match on this serve.

Cerundolo is in the same vein of form in his service game, taking a 30-0 lead. It becomes 40-0, with a fortunate bounce off the net.

Djokovic pulls a point back with one that just catches the line. Cerundolo misses one as Djokovic covers an unbelievable amount of ground, and it’s 40-30.

Djokovic wins another point with a well-timed drop shot and it’s deuce, a great response from the Argentinian gives him the advantage.

But a centimetre-perfect drop shot from Djokovic makes it a second deuce. Cerundolo fires a backhand wide, and Djokovic has what could be a key break point.

Djokovic has broken! Could that be the match?

Cerundolo’s shot goes long and Djokovic has the first point of his fourth service game of the fifth set.

Djokovic almost does the splits to make that shot here, that was an incredible effort to make the low volley. He smiles as he gets up after a quick swimming mime with his stomach on the clay.

A stunning effort forehand down the line and Djokovic goes 40-0 up, and he holds it to love, the first love-hold of the set.

Djokovic takes the first point, but it’s level again the next.

Cerundolo is running Djokovic around, there’s a big grunt as he can’t get to one and it’s 30-30.

The Argentinian has to use his second serve but the return goes long, and he needs just one more to take the game.

Djokovic misses a drop shot, and it’s level again! This is turning into an epic contest.