Milos Raonic has taunted the established big four of men's tennis by proclaiming their all-conquering era is over.

Wimbledon has seen the rise of a new generation rubber-stamped and Canadian ace-race leader Raonic heads into his semi-final against Roger Federer without fear.

With Andy Murray and Rafael Nadal already out, Raonic and Grigor Dimitrov could be the men's finalists on Sunday.

First they must fend off the old guard of Federer and Novak Djokovic, but 23-year-old Raonic reports growing belief among younger players on tour that the long-time kingpins are "yours for the taking".

"I think you see it more in people's play and people's attitude when they step out on court," Raonic said.

"It's a big difference to where probably a lot of guys were maybe a year ago.

"It's an even bigger difference to where guys were two, three, four, five years ago, where there was a very tight stranglehold on who was winning those big tournaments."

Raonic has rained down a tournament-leading 147 aces in five matches to reach his first grand slam semi-final.

Ahead of tackling 17-time grand slam champion Federer, who has won all his eight previous Wimbledon semi-finals and gone on to win seven titles, Raonic vowed he would ignore the reputation of the 32-year-old Swiss.

"I'm going to step out there and I'm not playing the seven-time Wimbledon champion. I'm not playing a 32-year-old man. I'm not playing father of two sets of twins, which is a very low possibility I bet to do," Raonic said.

"I'm not playing the guy that's won whatever he's won, which I could probably list quite vividly.

"I'm playing a guy that is standing in my way of what I want to achieve, and I've got to focus on everything that's there, on the situation, how best to deal with it to give myself the best possibilities to achieve what I want.

"I guess that you can't really out-run time in one way.

"New guys have got to come up and they've got to step up. We've been doing better and better, especially throughout this year.

"It's good to be a part of it. It's nice to see that sort of human side to those four guys when you have to step up to face them, and to have a belief more so than ever that it's yours for the taking if you play well."

Raonic will leapfrog Murray in the world rankings on Monday, together with the Scot's conqueror Dimitrov, as the new breed begin to pick off the quartet who together have dominated the grand slams over the last decade.

He picked out Stan Wawrinka's triumph at the Australian Open in January as an omen this year would see a revolution.

Wawrinka is 29, so not part of the young crop, but he had been threatening to make a major breakthrough and overcame both Djokovic and Nadal in Melbourne.

"Beating Novak and Rafa in that same time, because you have to do it, I think that one was the biggest sigh of belief and relief for a lot of guys," Raonic said.

"You felt like, 'Okay, he did it. I feel like I compete well with this guy. Why can't I do it?'."

Raonic is conscious that Federer has beaten him in all four of their previous contests.

"But I haven't played him I think in more than a year, a year and a bit," the Canadian said. "So I think I'm a different player."

Federer is braced for the challenge, and knows his return of serve will be critical.

"It keeps him in the match," Federer said of Raonic's big delivery. "It doesn't matter almost how he plays his return game.

"Here, clearly on the grass with a serve like that, it's never going to be an easy match. That's where you then go back to your own game and say, 'I'll take care of my own serves and see what I can do on the return'."

Dimitrov heads into battle against Djokovic steeled by his stunning straight-sets victory over Murray, which ended the champion's title defence.

The Bulgarian has been urged by girlfriend Maria Sharapova to go on and lift the trophy, while Djokovic has opened the mind games by declaring 11th seed Dimitrov is "the man to beat".

Serbian Djokovic is determined that at the age of 27 he should have many years left at the top, but he is not blind to the creeping threat of the new generation.

"We have these youngsters coming up, fearless on the court, hitting the ball...not caring who is across the net," Djokovic, the 2011 Wimbledon champion, said.

"It's good. It gets more attention to new faces and to a new wave that is able to challenge the best and be contending for grand slam titles."