On-form Djokovic rolling back years with Federer and Nadal
Rafael Nadal and Roger Federer have spent the last 18 months holding the Grand Slam fort for the big four of men's tennis, and now Novak Djokovic has come back to join the party.
After two years of physical and mental struggles, the 12-time Grand Slam champion appears fit and confident and has dropped only one set on his way to the last eight.
That is one more than Federer and Nadal, and it would still need an upset for there to be a different outcome than a repeat of the classic 2008 final between that pair.
But if anyone is to prevent that happening, Djokovic appears the man most likely.
Despite their dominance, the trio have not all reached the same Slam semi-final since the French Open in 2012, and 1996 Wimbledon champion Richard Krajicek believes Djokovic's form is ominous for those looking to break through.
The Dutchman said: "The bad news would be for the youngsters if Novak really regains everything. Roger, two more years, it would be amazing if he can make the Olympic Games, because that's the only title lacking. But if Novak stays fit, he can dominate for another three or four years after that."
The other member of the big four, Andy Murray, would love to be at the level Federer, Nadal and Djokovic are showing. His recovery from hip surgery is ongoing.
Djokovic, who has overcome an elbow problem, said: "I felt like in the last month and a half, the level of tennis has been very close to where I would like it to be, where I'm used to having it. So far the four matches have been really, really good for me. I haven't spent too much time on the court. I feel physically, mentally ready, fit, positive."
The next challenge for Djokovic is a quarter-final against Kei Nishikori, whom he has beaten 12 times in a row since the Japanese star claimed his biggest victory in the semi-finals of the US Open in 2014.
This will be their first meeting on grass, and Nishikori said: "I think it's going to be a new game for us. He's always like a big war for me."
Djokovic and Nishikori will play the first match on Centre Court on Wednesday, followed by arguably the pick of the quarter-finals between Rafael Nadal and Juan Martin del Potro, meaning Roger Federer must make a rare visit to Court One, where he faces eighth seed Kevin Anderson.
Del Potro was the only one of the quarter-finalists in action on Tuesday as he finished off a tough four-set victory over Gilles Simon.