London - Andy Murray and Roger Federer will look to reach the Wimbledon final on Friday and preserve the iron grip of the sport's 'Big Four' which has endured since 2003.
After Lleyton Hewitt triumphed 14 years ago, the following 13 men's titles have been shared between Federer, Murray, Novak Djokovic and Rafael Nadal.
The four heavyweights have also filled eight of the last 10 runners-up spots.
Standing in the way of 2013 champion Murray and seven-time winner Federer getting to Sunday's final are Tomas Berdych, the 2010 runner-up, and sixth seed Milos Raonic.
Berdych trails Murray by 8-6 in career meetings while Federer has a 9-2 lead on Raonic, the youngest of the four semi-finalists at 24.
Second seed Murray needed a tough five-setter to get past Jo-Wilfried Tsonga and reach his seventh Wimbledon semi-final and 20th at all the majors.
Friday's match throws up a new dynamic as he and 10th seed Berdych have never met on grass.
"I'll have to see some of his matches to get an idea of maybe some of the things he does differently on the grass courts, what his strengths are, maybe some of the things he struggles with a bit," said 29-year-old Murray, who has already been runner-up this year at the Australian and French Opens.
"Obviously he's a big guy who serves well. When he's dictating the points, he hits a big, big ball. He's a powerful guy.
"Ideally, I don't want to have him dictating all of the points because then I'll be doing a lot of running."
With defending champion Djokovic, who beat him in Melbourne and Paris, a shock third round loser at Wimbledon, Murray is the favourite to capture a third major on Sunday.
Berdych has an impressive 57 grass court wins in his career and has been a permanent fixture in the top 10 for six years.
He admits that he has watched Murray's development very closely.
"I think at the beginning, he was a bit more defensive, playing a little bit more just waiting for what the opponent's going to do" said the 30-year-old Czech.
"Now he is more aggressive, way more creative."
Federer, bidding for a record eighth Wimbledon title and 18th Grand Slam trophy, almost came unstuck in the quarter-finals.
He saved three match points and came back from two sets down to defeat 2014 US Open champion Marin Cilic to stay on course for a first major since lifting a seventh Wimbledon four years ago.
The third-seeded Swiss is, at 34, the oldest man in the semi-finals since 39-year-old Ken Rosewall finished runner-up to Jimmy Connors in 1974.
Federer is into his 11th Wimbledon semi-final and on Wednesday secured a record-setting 307th match win at the Slams.
He admits that his progress to the semi-finals has surprised him after a back injury forced him to skip the French Open.
It was the first Grand Slam he had missed since 1999 and came in a year where he has yet to win a trophy.
His only final appearance was in Brisbane in January where he lost to Raonic.
"I was very worried coming here," he admitted.
"I think it was huge for me to play the seven matches I did in Halle and Stuttgart.
"Then knowing that I had a week in between, if I get through the first week at Wimbledon, who knows. I put myself in that position perfectly without dropping sets, which was a big surprise to me.
"Next thing you know, it's like you're in the semis. You're really deep into the tournament. Yes, I did surprise myself, in quite a big way actually."
Federer has beaten Raonic twice on grass, the last time at Wimbledon in 2014 in what was the Canadian's first appearance in the last four.
"Definitely a great opportunity. Two years have passed since I played him here in the semi-finals. I'm happy that I have another shot at him," said the Canadian.