Serena Williams speaks at a news conference after announcing her withdrawal from the French Open. (Pauline Ballet/Associated Press)

PARIS — Even on a French Open Monday chockablock with stars and enticements, one goody managed to tower above the rest: Serena Williams vs. Maria Sharapova, tucked into the fourth round and slated to come fourth on the main Court Philippe Chatrier.

Then, moments before it would begin, it never did.

Williams, in her 67th Grand Slam tournament dating from 1998, had to announce a first: her withdrawal from singles competition during a major tournament. That trailed another first, her first as a mother, and her first Grand Slam appearance after missing the previous four.

“Yeah, unfortunately I have been having some issues with my [pectoral] muscle, and it has unfortunately been getting worse to the point where right now I can’t actually serve,” she said. “It’s kind of hard to play when I can’t physically serve.”

She spoke in the interview room indoors while, outdoors, Rafael Nadal was finishing off a booming young German left-hander, Maximilian Marterer, to reach the men’s quarterfinals after a harder-than-usual 6-3, 6-2, 7-6 (7-4) slog.

Just like that, Sharapova had reached the women’s quarterfinals in a  walkover, an odd passage to her first Grand Slam quarterfinal since returning from a doping suspension in April 2017.

By the time the announcement was made outside on the main court, moments after Williams finished speaking, Nadal had finished speaking in his post-match interview, and the crowd had scattered, most apparently aware already that a less-shiny men’s match would follow.

Given the threat of rustiness, Williams, 36, had thrived here. With her unaccustomed world ranking of No. 451, the 23-time Grand Slam winner had beaten No. 70-ranked Kristyna Pliskova, 7-6 (7-4), 6-4, and then No. 17-ranked Ashleigh Barty, 3-6, 6-3, 6-4, and then No. 11-ranked Julia Goerges, 6-3, 6-4.

“It didn’t start before I got here,” Williams said of the pain. “The first time I felt it was Goerges in my last match. That’s when I started to feel it. It was really painful, and I didn’t know what it was. In my doubles [match Sunday, a third-round loss while partnered with sister Venus], I tried a lot of different tapings, and I tried lots of different types of support to see how it would feel under match circumstance. It didn’t really get a lot better.”

She said it was an injury she had never felt before, that she doesn’t “really know how to manage it yet,” and she feels “clueless as to what to do” at this point, that she would have an MRI exam Tuesday, and that her disappointment felt vast.

“I’m beyond disappointed,” she said. “I gave up so much, from time with my daughter to time with my family. I put everything on the court, you know, all for this moment. So it’s really difficult to be in this situation, but I always, for now in my life, I just try to think positively and just think of the bigger picture and hopefully the next events and the rest of the year.”

She had those thoughts instead of thinking her usual way into a familiar quasi-rival with whom she shares a long and crowd-familiar history, and against whom Williams holds a 19-2 record. That includes 18 match victories in a row, stringing all the way back to the 2005 Australian Open semifinals. It includes 15 straight-set wins in that span, and those 15 include the past seven in a row. It includes the 2013 French Open final, which Williams won, 6-4, 6-4.

Still, their match presented the tournament with two queens of the game, with 28 combined Grand Slam titles, taking the court together.

Instead, Sharapova, who won the French Open in 2012 and 2014, would go on against Garbine Muguruza, the two-time Grand Slam champion who won here in 2016.

Williams had been rolling in the singles competition, right into anticipatory inquiries from reporters about past spats and her history with Sharapova. A reporter from Inside Tennis even managed to bring President Trump into the mix Saturday, with the president once saying Williams had been “intimidated” by Sharapova’s “supermodel looks.” It was an odd question that brought accusations of sexism against Bill Simons, the writer.

Williams was having nothing to do with his question, saying she has not been intimidated by anyone.

On Sunday night, Simons — the editor and publisher of Inside Tennis — offered an apology “if my awkward question seemed to empower Trump or attack Serena,” he tweeted. “I SO admire her. I’ve spent [my] lifetime fighting racism/sexism/homophobia.”

For Williams and Sharapova, there are always other matters. Like the book. The baby. The drug suspension. The old comments about boyfriends. Over the weekend, after they had advanced to the fourth round, Williams was asked about that book, the one written by Sharapova. Among other things in “Unstoppable: My Life So Far,” which was published last year, Sharapova wrote that Williams had sobbed after losing the 2004 Wimbledon final to her and claimed that Williams had promised she would never lose to that “little b—-” again.

On Saturday, Williams called the idea that she had been in tears after a loss normal and added, “I didn’t expect to be reading a book about me that wasn’t necessarily true.”

But Williams also said she bore no ill will toward Sharapova, the 28th seed and 30th-ranked player in the world. “Especially having a daughter, I feel like negativity is taught,” she said. “I feel like women, especially, should bring each other up.

“A lot of people always assume that I feel a different way, and it’s not true. If anything, I feel like we should encourage each other, and the success of one female should be the inspiration to another, and I have said that a thousand times. So for me, I always get inspired by other women that are doing well.”

Five years ago, the two exchanged cutting remarks over rumors about whom they were dating. That’s how badly their relationship had deteriorated. Still, so much has happened since then. “I think, to some extent, we have driven each other. Maybe that’s better than being friends. Maybe that’s what it takes to fire up the proper fury,” Sharapova said. “Only when you have that intense antagonism can you find the strength to finish her off. But who knows? Someday, when all this is in our past, maybe we’ll become friends. Or not. You never can tell.”

First, though, their on-court reunion will have to wait. “Yeah, it’s just very difficult because I love playing Maria,” Williams said. “It’s just a match I always get up for. It’s just her game matches up so well against mine.”

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