Early in the second set of the 2004 Wimbledon final, an extraordinary thing happened:
This was when Williams was close to her peak, having won five majors in the previous two years and pretty much cornered the market on muscular intimidation. Sharapova? She was a slender 17-year-old playing a limited schedule mandated by the WTA.
Sharapova stunned Williams 6-1, 6-4.
"I never, never in my life expected this to happen so fast," the second-youngest Wimbledon champion ever said. "To tell you the truth, I don't know what happened in the match. I don't know how I won. I was in my own little world -- I don't know what world that was, really."
At the time, that low screamer felt like a warning shot.
Sharapova went on to win the U.S. Open two years later and, two years after that, the Australian Open. But then, after winning three Grand Slam singles titles in a span of 15 majors, she dropped off the grid. Sharapova went 0-for-the-next-15.
And now, after triumphantly completing her career Grand Slam with the title at Roland Garros, she returns to the All England Club, where it all began. After career-threatening shoulder surgery and an agonizingly prolonged comeback, Sharapova is again back on top of tennis.
"She basically said, 'I am not going away. No, no, no,' " Tennis Channel analyst Mary Carillo said. "You've got to give it to Maria in that she has never taken her eye off the ball, literally or figuratively. She always had it in her head she was going to get back to this place; she never dropped the ball.
"I certainly think she can win Wimbledon," Carillo said. "Absolutely. The U.S. Open a second time? Sure. Does that answer your question?"
Carillo likens Sharapova's journey to that of Andre Agassi's, who, after winning three majors from 1992 to 1995, went through a difficult three-year period.
"Andre and Maria didn't mind the process [of the comeback]," Carillo said. "Andre said, 'All right, I still have tennis in me; I can win majors. I can take that ride being [ranked No.] 141 in the world. I will play Challengers.'
"He didn't need to do it, and neither did Maria. It had to be hard to be hitting all those double faults and wondering if her serve would ever get better."
It's hard to believe she turned 25 in April and that this is her 10th season as a professional. There are three older women in the top 10: Williams, Samantha Stosur and Marion Bartoli. A fourth, Sara Errani, is only 10 days younger than Sharapova.
Four years after the fact, Sharapova's back to the No. 1 ranking, and the question begs itself: Can she, will she be the dominant, full-year No. 1 that the WTA has lacked since Justine Henin's run of 61 straight weeks in 2007-08?
"[Victoria] Azarenka had a great run at the beginning, but then what happened?" Carillo said. "[Petra] Kvitova wins Wimbledon and basically goes away. Li Na same thing. Stosur, too. You think they'd like it more up there.
"Maria and Serena are the only ones who have shown a taste for longevity. Can she sustain herself at the No. 1 spot? There are a lot of interesting questions coming into Wimbledon. I picked Serena to win in the French. Hey, I was off by a mere seven rounds. Someone is going to have to prove to me that Serena can't win anything she sets her sights on."
That someone at Roland Garros was Virginie Razzano, who stunned Serena in the first round. At Wimbledon, her power will be rewarded on the living grass. Azarenka (a semifinalist a year ago) and defending champion Kvitova, too, will find a surface more conducive to their games.
Sharapova is coming off the best clay season of her life; she won 19 of 20 matches and three titles. Her eight victories against top-10 players already are the most she's had in a season since 2006.
Another sign of her growing dominance: She is trying to become the first woman to reach the finals at the season's first three majors since Henin in 2006.
Sharapova was undeniably emotional after winning at Roland Garros, something we haven't seen since that breakthrough eight years ago at Wimbledon. But when she met the media after that final triumph, Sharapova had recovered her cool command.
"I believe in my game," she said. "I think that's one of the reasons why I'm sitting here with my fourth one and winning Roland Garros, is because I always believed I could."
Another warning shot, perhaps?
"It's not over yet," Sharapova advised. "I'm not sitting here and saying I'm done, because I'm far from it. I have a lot more in me to achieve."