Novak Djokovic wants to win the French Open in the memory of his former coach and mentor, Jelena Gencic.
Gencic spotted Djokovic’s talent as a six-year-old in Serbia and remained an important person throughout his life.
She died of a heart attack on Saturday and Djokovic’s team kept the news from him until after he had beaten Grigor Dimitrov because they knew it would hit him hard.
The world No 1 immediately cancelled his press commitments but spoke movingly and eloquently after beating Philipp Kohlschreiber in the fourth round.
Djokovic said: “It hasn’t been easy, but this is life. Life gives you things, takes away close people in your life, and Jelena was my first coach, like my second mother.
“We were very close throughout my whole life and she taught me a lot of things that are part of me, part of my character today, and I have the nicest memories of her.
“This is something that will stay forever and hopefully I will be able to continue on and follow up where she stopped with her legacy, because she left so much knowledge to me and to the people that were close to her.
“She never got married, she never had kids, so tennis was all she had in life. She was 77 years old and before she passed away two days ago, last week she was giving lessons to kids. She’s one of the most incredible people I ever knew.
“I feel even more responsible now to go all the way in this tournament. I want to do it for her, also.
“I remember the last conversation we had two weeks ago about Roland Garros. She told me, ‘Listen, you have to focus, you have to give your attention to this tournament. This is a tournament you need to win’.
“She was giving me this kind of inspiration and motivation even more. So now I feel in her honour that I need to go all the way.”
The French Open is the only Grand Slam title Djokovic has not yet won, and he survived his first real test, coming from a set down in cool and windy conditions to defeat German Kohlschreiber 4-6 6-3 6-4 6-4.
In the last eight Djokovic will meet Tommy Haas, who reached his first quarter-final at Roland Garros at the age of 35 with a thumping 6-1 6-1 6-3 victory over Mikhail Youzhny.
The victory makes German Haas the oldest men’s singles Grand Slam quarter-finalist since Andre Agassi at the US Open in 2005 and the oldest at the French Open for 42 years.
Haas said: “These are cool stats sometimes to hear and to know about. It makes you proud. But what I’m really proud of is that I reached the quarters here for the first time, not knowing if that was ever going to be possible.”
The 12th seed has been dogged by injury throughout his career and two years ago dropped off the rankings altogether.
Last year he had to qualify for the tournament but he is now on the verge of a return to the top 10 for the first time since 2007.
Rafael Nadal has been below par so far this tournament but he chose his 27th birthday to show more of the form that has brought him seven titles at Roland Garros.
The Spaniard’s fearsome forehand had more bite and his movement was sharper as he dispatched Japan’s Kei Nishikori 6-4 6-1 6-3 before a giant birthday cake was brought out on to Court Philippe Chatrier.
The best match of the day on paper looked to be Stanislas Wawrinka against Richard Gasquet, and it certainly did not disappoint, with a combined 149 winners hit.
Wawrinka and Gasquet are two of the game’s most stylish exponents and the Swiss eventually came through 6-7 (5/7) 4-6 6-4 7-5 8-6 in four hours and 16 minutes.
It was harsh on the Frenchman, who ran out of gas rather than heart, while Wawrinka, who now has to recover for a match against Nadal, has come back from two sets down at the French Open to win four times.