London - Roger Federer said on Wednesday that seeing Prince William and wife Catherine in the Royal Box on Wimbledon Centre Court helped inspire him to a record 32nd Grand Slam semi-final appearance.
Federer, the six-time champion at the All England Club, comfortably defeated Russia's Mikhail Youzhny 6-1, 6-2, 6-2 to set-up a semi-final clash with world number one Novak Djokovic.
Also in the Royal Box were Australian tennis legend Rod Laver, 50 years after he completed the Grand Slam, as well as golden couple Andre Agassi and wife Steffi Graf, both former Wimbledon champions.
"I really actually do enjoy seeing legends coming out, following Wednesday's tennis. Royals coming out, it's inspiring, too, in some ways, believe it or not," Federer explained.
"It's great for Wimbledon. It's great for the players. It's just nice to see that the Royal Box is always full. It's never empty for us. And if it is, you know they're going to come back, they're not here just to drink champagne and tea in the back.
"They really do come for the tennis. We feel that on Centre Court, and I do feel that. That's probably one of the reasons why I play well on Centre Court."
When asked if he can see himself following the likes of Agassi and Laver into the Royal Box, Federer said: "I don't know. First I'll have to get an invitation and then we'll see."
"I met Kate for the first time. William I've met again after Australia. They were very nice, very friendly," said Federer.
"Had a bit of a chat. What exactly, it's not so important I don't think. But it was a nice conversation."
The royal couple received a rapturous welcome from the crowd as they arrived in the front row of the box, having already proved a hit around the All England Club.
"My life is complete!," tweeted German women's player Anna-Lena Groenefeld.
"I don't care that we won the Mixed! Prince William said hi to me! I was so excited I won my service game!????"
Youzhny was also looking to the Royal Box for inspiration after slipping two sets down.
He spotted 1992 champion Agassi, sitting next to royal couple.
"Can you tell me what I'm supposed to do out here?," pleaded the 30-year-old, who went into Wednesday's match having lost all of his previous 13 meetings with Federer.
Federer said he enjoyed the light-hearted moment.
"It was pretty funny, you know, him speaking to the Royal Box," he said.
England football manager Roy Hodgson, whose side crashed out of Euro 2012 in the quarter-finals against Italy last month, was also in the box watching the men's action with his wife Sheila.
On Tuesday, Michael and Carole Middleton, the parents of the Duchess of Cambridge, had been treated to seats in the Royal Box.
It was a move up for Carole Middleton, who was in the regular seats on Centre Court when she visited the All England Club last Wednesday.
But when Catherine's siblings James and Pippa attended on Thursday, they were treated to the best seats in the house.
Last week, William's father Prince Charles visited the tournament for the first time since 1970. He was joined by his wife Camilla, the Duchess of Cornwall.