Novak Djokovic is wary of the threat "red hot" Wimbledon final rival Matteo Berrettini poses to his Golden Slam ambitions.

Chasing a sixth title at the All England Club, and bidding to become the fourth man in the Open Era to record a hat-trick of successive Wimbledon triumphs, Djokovic could hardly be set to face a tougher opponent.

Berrettini won the Queen's Club title on grass in June and has made good on many experts' prediction that he would be the player to come through the bottom half of the SW19 draw.

Should the 25-year-old Italian carry off the title, he would become his country's first singles champion at Wimbledon.

And although Djokovic starts as a heavy favourite, looking to join Roger Federer and Rafael Nadal on 20 grand slams, it is not so preposterous to think there could be an upset.

Berrettini leads the way in aces with 101 for the tournament, which puts him 38 ahead of Djokovic in third place on the list.

He has also been the second fastest server, sending down a delivery of 139mph. Djokovic sits top in terms of points won on first serve, his 85 per cent success record putting him a shade ahead of Berrettini, fifth with a very healthy 82 per cent.

There have been suspicions in the past that Berrettini had a limited game in terms of its dimensions, but he has put paid to that talk in recent times, showing admirable variation, which together with the confidence that is soaring makes him a genuine threat to the world number one.

Djokovic has not lost at Wimbledon against a fellow top-10 player since his defeat to Andy Murray in the 2013 final, and if he is seeking positive omens ahead of Sunday's Centre Court showdown that is certainly one, as is the fact he beat world number nine Berrettini in four sets in their French Open quarter-final in early June.

The 34-year-old from Belgrade is aiming to complete the third leg of a staggering bid to win all four majors and the Olympic Games singles title. The Golden Slam is a feat only ever previously achieved by Steffi Graf in 1988.

But Djokovic senses danger when he looks at Berrettini, more so than when they met on clay in Paris.

He pointed out: "Obviously grass favours him even more, favours his game. If he serves big, as he did throughout the entire tournament, it's tough to break his serve, it's tough to go into the rhythm, to find a good positioning to return, make him play.

"But I believe in my return. I think return has served me very well throughout my career. Hopefully I'll be able to get a lot of those serves back and wait for my chances."

Djokovic added: "It's really anybody's game. He's arguably the guy who has been in the best form on grass courts this year, winning Queen's. He's red hot. It's going to be a great battle."

It would be a sixth Wimbledon title for Djokovic should he claw his way past Berrettini, who is seeking a first grand slam title.

In the Open Era, only Pete Sampras, Bjorn Borg and Roger Federer have won three or more successive Wimbledon titles among the men, while Djokovic, in this potentially historic year of his, is bidding to become the first man since Rod Laver in 1969 to win each of the first three slams in a season.

Berrettini's career record does not come near to competing with that of the player who will stand on the opposite side of the net. On Sunday the Rome-born player will target a sixth tour title, and a third on grass.

Yet coming from Queen's Club, he was being told that a major opportunity awaited him at Wimbledon.

"I knew I could do it, but I didn't think I am going to do it because this is how I am," Berrettini said.

"I took every step really careful and slowly. I guess it was the right thing to do. Obviously the job is not done yet. I want to get the trophy now that I'm here."