Novak Djokovic’s search for his personal Holy Grail – a 25th Grand Slam title and an eighth title here – goes on. But only just.

He emerged victorious from a bruising three-hour, 11-minute battle with Flavio Cobolli 6-7(6), 6-2, 7-5, 6-4. He survived a painful tumble at the end of the fourth set.

He came through the barrage of forehands and big serves from the man 15 years his junior. And after all that, he has Jannik Sinner to face in the semi-final.

“First I have to say huge congratulations to Flavio for an amazing tournament and also a great battle today,” Djokovic said. “Great performance from him.

“I saw him play here, I knew he was playing well. He was playing on a really high level.

“I think what surprised me a lot is his serve. He was serving at a really fast pace and going for his shots. He’s such a talented and skilful player.

“He’s definitely of the guys we will be seeing in the future much more.

“It means the world to me that at 38 I’m still able to play in the final stages of Wimbledon. I’m going to have Sinner in the next round, that’s going to be a great match-up.”

Cobolli had two major obstacles to overcome, ones that are nothing to do with tennis as such but are more like rites of passage for the developing players.

The first was his debut on Centre Court.

Simply getting used to the size of the place takes time. Obviously the court dimensions are exactly the same as any court in the world but the space around the field of play seems massive.

And yet the whole stadium feels very intimate. It is unique but players tend to be creatures of habit: they like familiarity.

Then there was the business of backing up an impressive win. His celebrations after beating Marin Cilic to reach his first Grand Slam quarter-final were long and they were emotional – it was as if he had won the title.

To come down from that high and then recharge the energy banks for such an important match as this would have taken some doing.

But there was Cobolli and his flashing forehand, ripping returns and landing passing shots on a postage stamp.

He showed no fear and little respect for Djokovic’s reputation – in Cobolli’s mind, he was just playing another player on another court.

He wasn’t, though, and when the seven-time champion and winner of 24 Grand Slam titles broke for a 5-3 lead after 40 minutes, there was not a soul on court who imagined Djokovic would not be able to serve it out to take a one set lead. But he couldn’t.

A couple of returns from Cobolli, a couple of errors from Djokovic and they were back on serve.

The Italian’s service games were under constant pressure (he fended off a set point) but he held on and headed for the tie-break. There he drew first blood on the opening point and, after 68 minutes, converted his second set point.

That was when two decades of experience came into play.

Djokovic had seen all of this before: young challengers coming into his home-from-home and pushing him about. He knew what to do and what to expect.

At some point the younger man would have a dip; his concentration would waver. When it did, Djokovic would be waiting because his focus never changes.

Winning or losing, Djokovic remains the same.

One ragged service game from the Italian started the slide. Cobolli was broken and it was as if Djokovic had stuck a nail in a tyre: the wheel still goes round but the tyre slowly deflates.

Cobolli kept moving but his confidence was fading away.

Another break followed and the set was over in 26 minutes. Yet another break at the start of the third set might have spelled doom there, too.

Djokovic wore that familiar look, the one that says ‘this is my house and you are not welcome here’.

He made only two unforced errors in the second set; he was giving nothing away. So Cobolli lifted his game and took what he could – he broke back in the third set.

This turn of events did little for Djokovic’s mood. His team were left in no doubt about his feelings as he talked to them, shouted at them and growled to himself.

No matter, he was still ready and waiting when the Italian faltered again to hand over a 6-5 lead. Djokovic did not make any mistakes serving it out this time.

The errors were mounting for the young Italian as he tried to find a way through the brick wall at the other end of the court. His winners were spectacular; his work rate was laudable but Djokovic would not go away.

He has not gone away for the best part of the last 15 years and believing that Wimbledon is his best chance of winning that 25th Grand Slam title he so craves, he was not planning on doing so now.

Something had to be done.

Cobolli started to serve better, he tried to be a bit more aggressive with his groundstrokes. And still Djokovic stood firm.

Even when he slipped and fell, doing the splits and hurting his hip, on match point, he got up and stood firm. He always does.

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