Novak Djokovic believes destiny can help fire him past German veteran Tommy Haas and into the French Open semi-finals on Wednesday.
The top-seeded Serb needs a Roland Garros title to complete a career Grand Slam.
If he gets past 35-year-old Haas, he could meet seven-time champion Rafael Nadal in the semi-finals should the Spaniard beat Switzerland's Stanislas Wawrinka in Wednesday's other last-eight match.
Djokovic is determined to make the final for a second year to honour the memory of Jelena Gencic, his first coach, who passed away at the weekend.
"She was like my second mother," said the top seed.
"I feel even more responsible now to go all the way in this tournament. I want to do it for her because she was a very special person in my life."
Djokovic has a 4-3 winning record over Haas, including their only meeting on clay in Paris seven years ago.
But Haas, the oldest man since 1971 to get this far, also believes fate is on his side.
He has endured an injury-hit career and in his marathon third-round win over John Isner, he needed a record 13 match points to secure victory.
Nadal has a 9-0 career lead over 28-year-old Wawrinka who is playing in his first Roland Garros quarter-final.
Wawrinka is also playing for the honour of Switzerland following the shock exit of Roger Federer at the hands of Jo-Wilfried Tsonga on Tuesday.
Nadal, bidding to become the first man to win the same Grand Slam title eight times, arrived in Paris with six titles from eight finals after returning from a seven-month knee injury lay-off.
Nadal, who turned 27 on Monday, said he is now being bothered by an elbow problem.
"Little by little I'm gaining greater power in my serve. My elbow has improved throughout the week. I feel much better," said Nadal.
In the women's quarter-finals, defending champion Maria Sharapova faces Serbia's Jelena Jankovic.
The winner of that tie will take on either Maria Kirilenko or Australian Open champion Victoria Azarenka for a place in the final.
Sharapova has an imposing 7-1 career lead over Jankovic but this will be their first meeting on clay.
Both women were juniors at Nick Bollettieri's academy in Florida with Sharapova arriving from Russia as a nine-year-old while Jankovic was 12 when she pitched up from Belgrade to work with the renowned US coach.
But they are understood to have a strained relationship.
Azarenka is in her third French Open quarter-final but, unlike the other majors, she has never got beyond the last-eight stage.
Kirilenko will be playing in her first French Open quarter-final, having made the last eight at the Australian Open in 2010 and at Wimbledon in 2012.