After proclaiming herself the French Open favorite, Maria Sharapova found herself in danger of being the latest upset victim in the women's draw.

Maria Sharapova's perfect day helps her supplant Serena Williams as the No. 1 crowd favorite?

Until she did what favorites do and found another gear, which earned her a date against a foe that already accomplished what she has been unable to accomplish for 10 years.

Sharapova, the No. 7 seed at Roland Garros, lost the first set and trailed 4-3 in the second but rallied to win nine straight games from No. 19 seed and former U.S. Open champion Samantha Stosur for a 3-6, 6-4, 6-0 victory to advance to the quarterfinals for the fourth consecutive year.

"There are so many emotions you go through in a match, and then there are always moments where you feel a bit of a momentum change," Sharapova said, according to ESPN. "I think you feel a lot more as a player than maybe a spectator."

Serena Williams' loss entrenches Maria Sharapova as the favorite at Roland Garros

Even before No. 3 seeded Agnieszka Radwanska suffered her upset defeat in the third round, Sharapova emerged as the favorite when both No. 1-seeded Serena Williams (second round) and No. 2 Li Na (first round) already had been eliminated from the tournament.

Now, Sharapova turns her attention to 35th-ranked Garbine Muguruza, the 20-year-old from Spain who handed Williams her worst-ever Grand Slam defeat, a 6-2, 6-2 thrashing in the second round.

Sharapova should be considered a big favorite, but she has not been able to beat Serena since 2004 and has lost 15 straight to the world's No. 1 player. A win over Muguruza would be a big step -not only for Sharapova's confidence but also for her quest for her second French Open title and fifth Grand Slam title overall.

Sharapova has won each of the Grand Slam events once.

"I love competing. That's one of the best parts of the sport. Gives me the greatest pleasure, and I don't think anything else in life can give me that," ESPN.com reported Sharapova as saying. "I'm using that to my advantage while I can."