Novak Djokovic braced himself for the "ultimate challenge" of stopping Roger Federer after coasting past Florian Mayer to reach the last four of Wimbledon.
Mayer, ranked 29th in the world, played some excellent tennis against Djokovic on Court One at times but the defending champion proved too strong in the end as he recorded a 6-4 6-1 6-4 win.
The victory set up a mouthwatering semi-final for Friday against six-time champion Federer, who tore Mikhail Youzhny's game apart in front of the Duke and Duchess of Cambridge on Centre Court.
Federer is practically regarded as royalty at Wimbledon, and in the world of tennis.
The Swiss has won 16 grand slams and is determined to equal Pete Sampras and William Renshaw's record of winning seven Wimbledon titles.
Federer may be 30 years old, but Djokovic insists his next opponent's power is not on the wane.
"He's rated probably as the best player in history," Djokovic said. "He has won everything that a tennis player can win and he's coming back for more.
"He has won the most grand slams in history so it is the ultimate challenge for me. Roger has been on the top of the men's game for so long.
"He has won six titles here and he definitely wants to prove to himself and to everybody else that he can win it once again."
Djokovic displayed some of the best tennis he has played throughout the Wimbledon fortnight against Mayer.
The Serbian started slowly, coming from a break down to clinch the first set before easing to victory in one hour and 45 minutes.
Djokovic has dropped just one set en route to the semi-final and has warned Federer he is in supreme form ahead of their clash, which will be the first time the pair have met at Wimbledon.
"My mindset is very positive," Djokovic added.
"He has a really smart game for this surface, but I have improved playing on grass in the last couple of years.
"I won the title here last year and have got to another semi-final this year, so I'm feeling good about this surface, and about myself.
"This year I've been playing really well, constantly well, from the start of the tournament, and I hope to continue that way.
"I really have nothing to lose. I'm going to try to win."
Djokovic has had the edge over Federer in their recent meetings, winning six out of the last seven matches.
He also has the psychological advantage of knowing he has come from match point down on two occasions against Federer at the US Open.
"Most of our matches that we play against each other are very close," Djokovic said.
"Very few points decide the winner. I won two years in a row against him with match points down.
"I expect this match to be a tight one.
"We have never played on grass, so I think it's going to be interesting for both of us to see what happens."
Had Mayer taken his chances, Federer could have perhaps been facing a different opponent in the last four.
The German accepted he deserved to lose in the end, however, and thinks Federer will be desperate to beat Djokovic to snatch back the world number one ranking he held for so long.
"Getting the number one ranking will motivate him," Mayer said.
"But I think Roger also has to play on a really high level to have a chance to beat Novak."
