World's best serve up Friday French Open special

Djokovic is on a staggering 43-match unbeaten run stretching back to the Davis Cup final in December Rafael Nadal, Novak Djokovic, Roger Federer and Andy Murray, the world's most accomplished players, serve up a French Open semi-final special on Friday with a series of records at stake. Djokovic, on a staggering 43-match unbeaten run stretching back to the Davis Cup final in December, will depose Nadal as world number one with victory over 2009 Roland Garros champion and 16-time Grand Slam title winner Roger Federer.
Victory will also see him equal John McEnroe's 1984 mark of a 42-match winning start to a year.
But he faces a rejuvenated Federer, seeded outside the top two for the first time since Wimbledon in 2003, who has reached his sixth Roland Garros semi-final without dropping a set.
"A match between the greatest player ever and the greatest player of the moment," was how Nadal described the Federer-Djokovic clash.
Defending champion Nadal, who will turn 25 on Friday, is just two wins from equalling Bjorn Borg's record of six French Open titles.

He takes on fourth seeded Murray who can become the first British man since Bunny Austin in 1937 to reach the title match if he defeats Nadal for the first time on clay.
Second seed Djokovic trails Federer 13-9 in career meetings, but has won all of their three matches in 2011, including a straight-sets triumph over the great Swiss in the semi-finals of the Australian Open on his way to the title.
The Serb hasn't played since Sunday after scheduled quarter-final opponent Fabio Fognini pulled out of their scheduled clash with a leg injury.
But he insists that his unexpected break will not harm his chances against Federer.
"I'm happy with my game. I'm playing the best tennis of my life at the moment," said Djokovic.
Federer, without a Grand Slam title since the 2010 Australian Open, has cruised effortlessly through the tournament, enjoying the spotlight being trained brightly on Nadal and Djokovic.
"There's less at stake for me than for Novak," said Federer, the last man to beat the Serb at the World Tour finals in London in November last year.
"He's got a lot of things going on. I'd love to be in a Grand Slam final, because I haven't achieved it for a few Slams, but it's nothing major for me, as long as I keep playing well."

Nadal dropped 53 games on his way to the quarter-finals, the most he has conceded in his Roland Garros career.
But in taking his tournament record to 43 wins against one just defeat in beating Robin Soderling -- the man who caused that blemish in 2009 -- the Spaniard put on his best performance so far.
His 6-4, 6-1, 7-6 (7/3) last eight win saw the Nadal of old with his spell-binding mixture of destructive, pinpoint accuracy off both wings and impregnable defence from the baseline.
Nadal has a 10-4 record over Murray and has won all three meetings on clay including as recently as the Monte Carlo Masters in April.
Murray has been carrying an ankle injury after hurting himself in the third round against Michael Berrer, but Nadal believes that will not be an issue.
"It is not limiting when you are playing, because you just resist the pain a little bit," said Nadal.
"Playing Andy is always a big challenge, because you know how good he is. He has all the shots. He can defend very well; he can attack very well.
"You have to play at a very high level to beat him. It's not going to be impossible."
Murray charged into the semi-finals for the first time with a 7-6 (7/2), 7-5, 6-2 win over Argentinian veteran Juan Ignacio Chela.
He is just the second British player to reach the last four in Paris in the Open era (since 1968) after Tim Henman did so in 2004.
Murray, who came within two points of defeating Djokovic at the Rome Masters, admits he is surprised to be in the last four, the first time since the 2006 French Open that the top four seeds have made the semi-finals of a Grand Slam.
"With everything else that's been going on I'm a little surprised to be still here as I haven't been playing particularly well," said the Scot.
Murray appreciated the challenge ahead and admitted he is a fan of Nadal's famous spirited attitude on court.
"I know Rafa will play excellent tennis against me on Friday. Pretty much every time we've played we've had some really good matches and he's always played well.
"Even in practice he plays well against me," he added.