(CNN)When it comes to the French Open lately, Maria Sharapova is old reliable.
Once describing herself as a "cow on ice" when trying to navigate the clay, Sharapova has made three consecutive finals at Roland Garros, winning twice, including last year.
But Friday, on paper, brought a potentially tricky encounter for the Russian: She faced Samantha Stosur in the third round.
Even though Sharapova led their head-to-heads 14-2, the Australian held a set and break advantage on the world No. 2 when they faced off at the season's second major 12 months ago.
Stosur knows how to play on clay, landing in the French Open final in 2010 and reaching two other semifinals. Her "heavy" forehand particularly suits the surface, along with a powerful kick serve.
She isn't nicknamed "Bam Bam" for nothing.
Further, three big names in the women's field -- Simona Halep, Caroline Wozniacki and Eugenie Bouchard -- exited the tournament in the previous three days. Perhaps the craziness would extend to Sharapova.
And when Stosur broke first in yet another chilly, windy day in Paris, no-one was discounting another upset.
Sharapova, however, wore down Stosur -- playing some fine defense in the process -- and made the last 16 with a comfortable 6-3 6-4 victory. That despite continuing to battle a cough.
"I was just really happy to win this one," the 28-year-old, who plays Lucie Safarova on Sunday, told reporters. "I knew it was going to be a tough one going into the match. I knew I had a tough opponent, and I just wanted to be as ready as I could."
Hours after Sharapova's tussle, Carla Suarez Navarro fell to Flavia Pennetta 6-3 6-4 in yet another sizable upset. Spain's Suarez Navarro, a dark horse, entered the French Open fourth in the calendar year standings, and her favorite surface is clay.
All the upsets have opened up the draw for Ana Ivanovic, who was once almost as good as Sharapova on clay, and won the title in 2008.
A wrist injury and loss of form led to a skid for the Serb but 2014 served as a rebirth for the former world No. 1 as she contested six finals, winning four. However, her best recent grand slam performance was a quarterfinal in Australia 16 months ago.
But opportunity is knocking for the 27-year-old, who powered past Donna Vekic 6-3 6-0 Friday. The Croatian teen had opened her Paris campaign by beating Caroline Garcia, who is 3-0 against Ivanovic this year.
Halep, a possible quarterfinal opponent for Ivanovic, then fell to Mirjana Lucic-Baroni.
Ivanovic's next challenger is ninth seed Ekaterina Makarova. The Russian has ousted the likes of Ivanovic, Serena Williams and Victoria Azarenka at grand slams but tends to struggle on clay.
"Every grand slam, every tournament, there are lots of upsets on paper, but every player can perform well," Ivanovic, watched by boyfriend Bastian Schweinsteiger, told reporters. "So you can't underestimate anyone. No matter who I play, it's going to be another preparation, another day to look forward to and challenge."
France hasn't had a women's winner since Mary Pierce in 2000, or a men's champion since Yannick Noah in 1983, but the host nation is still alive on both fronts.
Jo-Wilfried Tsonga, considered the leader of the French men's pack, eased past Pablo Andujar 7-6 (3) 6-4 6-3 to set up a match with former French Open semifinalist Tomas Berdych.
The ever dramatic Alize Cornet moved into the fourth round by ousting Lucic-Baroni 4-6 6-3 7-5. Cornet -- who owns wins over Halep and world No. 1 Williams -- has a winnable clash on Sunday, too, up against inexperienced 19th seed Elina Svitolina.
Cornet's Fed Cup teammate Kristina Mladenovic contests her third-round match Saturday against 88th-ranked Belgian Alison Van Uytvanck.
Gilles Simon and Richard Gasquet progressed Friday after winning five-setters. Simon edged fellow Frenchman Nicolas Mahut 6-2 6-7 (6-8) 6-7 (6-8) 6-3 6-1 to reach the fourth round, where he faces Swiss eighth seed Stanislas Wawrinka.
Gasquet faces South Africa's Kevin Anderson in the third round, having completed a 3-6 6-3 6-1 4-6 6-1 win over Argentina's Carlos Berlocq. Darkness halted their encounter after the fourth set Thursday.
Roger Federer hails from Switzerland but the French love the 17-time grand slam champion like their own, memorably helping him to victory over Novak Djokovic in a raucous 2011 semifinal.
On Friday, the second seed cruised for the third consecutive round, seeing off Damir Dzumhur 6-4 6-3 6-2 in around 90 minutes.
Federer gets his first real test in the last 16 against another home hope, Gael Monfils. Monfils has beaten Federer twice in a row, both on clay.
Monfils sealed his spot in the fourth round just before 9 p.m. local time, rallying to overcome the clay-court proficient Pablo Cuevas 4-6 7-6 (1) 3-6 6-4 6-3. Cuevas led 4-1 in the fourth set -- two breaks to the good -- but then imploded to the delight of the crowd, which included the head of French tennis, Jean Gachassin.