Serena Williams and Maria Sharapova bring their career-long bitter feud to Roland Garros on Monday with the bad blood between the sport's two iconic stars threatening to boil over.
Sharapova has not defeated her fellow former world number one since 2004 -- a streak of 18 matches -- the same year she made her global breakthrough at Wimbledon as a slender teenager prone to fits of giggles.
The 22nd match of their one-sided rivalry will once again be played out against a familiar soundtrack of suspicion and public bickering.
Williams, the three-time French Open champion and 23-time major winner, has vented her anger at Sharapova's claims that she wept after losing the 2004 Wimbledon title match.
The 36-year-old described references to her in Sharapova's memoir, 'Unstoppable', as "100 percent hearsay".
Williams is furious that Sharapova went public with events from behind closed doors at the All England Club.
"I think Serena hated me for being the skinny kid who beat her, against all odds, at Wimbledon," Sharapova wrote.
"Not long after I heard Serena told a friend, who then told me, 'I'll never lose to that little bitch again'."
Williams is also angry as Sharapova's claims came just months after the American had hailed her for the manner in which she announced her failed drugs test at the 2016 Australian Open.
"I was one of the few people that said she was brave to say something," said Williams referring to Sharapova's "drug incident".
"I didn't have anything negative to say about Maria."
Sharapova's test for meldonium led to a 15-month ban.
Ironically, the Russian's last match before her suspension was against Williams in the quarter-finals in Melbourne.
Williams has monopolised their on-court clashes for the last 14 years so much so that Sharapova has taken just one set in a decade.
Despite that, the Russian, with five Slams to her name, still brings in the serious money.
- 'Black heart' -
Her net worth was valued at $285 million by Forbes last year while, according to The Richlist, Williams's financial assets were estimated at $170 million.
As well as vying for commercial and PR supremacy, the two have fought very public battles over their private lives.
On the eve of Wimbledon in 2013, Williams gave an explosive interview to Rolling Stone magazine in which she left nobody in any doubt as to her target.
"She begins every interview with 'I'm so happy. I'm so lucky' ? it's so boring," said Williams without namechecking the Russian.
"She's still not going to be invited to the cool parties. And, hey, if she wants to be with the guy with a black heart, go for it."
The 'black heart' was a not so subtle reference to Bulgarian tennis player Grigor Dimitrov, a rumoured former boyfriend of Williams, who was then dating Sharapova.
A few days later, Sharapova aimed a trademark icy riposte at Williams.
"If she wants to talk about something personal, maybe she should talk about her relationship and her boyfriend that was married and is getting a divorce and has kids," she said in reference to Patrick Mouratoglou, who is still Williams's coach but was reportedly her boyfriend at the time as well.
Williams, playing her first Slam since winning the 2017 Australian Open and giving birth to daughter Olympia in September, insists Sharapova is favourite to win Monday's match on Court Philippe Chatrier.
Two-time Paris champion Sharapova, meanwhile, is wary of the enormity of the routs she has suffered.
"I think there is a lot of things in her game that she's done much better than I have. Numbers don't lie," said the 31-year-old.
Meanwhile, world number one Simona Halep, the runner-up in 2014 and 2017, tackles Belgian 16th seed Elise Mertens for a place in the last-eight.
Mertens is on a 16-1 red clay run this year. However, her only loss was to Halep in Madrid where she pocketed just three games.
The winner of that clash will take on either German 12th seed Angelique Kerber or Caroline Garcia, the seventh-seeded Frenchwoman who made the last-eight in 2017.
Third seed Garbine Muguruza of Spain, the 2016 champion, faces unseeded Ukrainian Lesia Tsurenko who has never got beyond the last-16 at the majors.
Best of enemies: Maria Sharapova and Serena Williams who will meet again at the French Open on Monday
Power-packed: Top seed Simona Halep returns the ball to Belgium's Elise Mertens during their fourth round match on Monday