Paris, France (SportsNetwork.com) - Reigning champion Maria Sharapova and former titlist Ana Ivanovic were a pair of third-round winners Friday at the French Open.

The second-seeded former world No. 1 Sharapova took out 26th-seeded former U.S. Open champ and former Roland Garros finalist Samantha Stosur of Australia 6-3, 6-4, while the seventh-seeded former top-ranked star Ivanovic whipped Croatian teenager Donna Vekic 6-0, 6-3 in 53 minutes at the year's second Grand Slam event.

The career Grand Slam winner Sharapova topped Stosur in a fourth-round affair in Paris last year in a match the tall Russian was six points away from losing. Sharapova now leads their lifetime series, 15-2.

"I was just really happy to win this one," Sharapova said. "I knew it was going to be a tough one going into the match. I just wanted to be as ready as I could, and I was really happy I was able to win it.

"Against Sam I know I have to take care of my service games because she's capable of serving really well. I'm also a tall girl, so the kick she's able to give on the second serve maybe doesn't bother me as much as other players. I quite like that ball. But we've had many tough matches despite my record, and it's not something I look at very lightly when I go up to that match. I know I have to beat a good player.

"She's been playing really well and loves playing here. So I thought it was a great result for me."

Stosur was fresh off her clay-court title in Strasbourg.

This year's Australian Open runner-up Sharapova has appeared in the last three French Open finals, including titles last year and in 2012. She was the 2013 runner-up here to Serena Williams.

Sharapova's fourth-round opponent on Sunday will be Czech Lucie Safarova.

Ivanovic, the 2008 champ and 2007 Roland Garros runner-up, won the first seven games in her match against Vekic and finished with only 11 unforced errors. The Serbian star is in the round of 16 at a Grand Slam for the first time since last year's Aussie Open.

The 18-year-old Vekic was appearing in her first third-round match at a major.

Up next for Ivanovic will be dangerous Russian Ekaterina Makarova.

For the fourth time this week a top-10 player exited the draw, as 28th-seeded Italian Flavia Pennetta toppled eighth-seeded Spaniard Carla Suarez Navarro 6-3, 6-4. Suarez Navarro joined third-seeded Simona Halep, fifth-seeded U.S. Open runner-up Caroline Wozniacki and sixth-seeded Wimbledon runner-up Genie Bouchard on the sidelines.

Meanwhile, the ninth-seeded Makarova handled fellow countrywoman Elena Vesnina 6-2, 6-4 and a 13th-seeded Safarova tackled 20th-seeded former Wimbledon runner-up Sabine Lisicki of Germany 6-3, 7-6 (7-2).

Makarova is trying to reach her seventh Grand Slam quarterfinal in her last 14 majors. She appeared in the semis at the previous two Slams -- the U.S. and Aussie Opens.

Another upset came when 21st-seeded rising Spaniard Garbine Muguruza took out 11th-seeded German Angelique Kerber, 4-6, 6-2, 6-2. Muguruza will battle Pennetta in the round of 16.

In other third-round play, 19th-seeded Ukrainian Elina Svitolina beat German Annika Beck 6-3, 2-6, 6-4 and 29th-seeded French crowd favorite Alize Cornet rallied for a 4-6, 6-3, 7-5 win over Croatia's Mirjana Lucic-Baroni, who stunned last year's French Open runner-up Halep on Wednesday.

Cornet is into the fourth round at her home major for the first time in 11 attempts.

"At last, I'm into the second week at Roland. I've been waiting for this for 11 years," she said.

Cornet will face Svitolina on Sunday.

On Saturday, the world No. 1 Williams will face 27th-seeded former top-ranked star Victoria Azarenka and fourth-seeded two-time Wimbledon champ Petra Kvitova will encounter 30th-seeded Romanian Irina-Camelia Begu in the third round.

Williams owns two French Open titles among her 19 Grand Slam wins. She currently holds the Aussie and U.S. Open crowns, is a sizzling 27-1 this year, and has won her last 16 matches at the majors.

The 33-year-old is 15-3 lifetime against Azarenka, including 8-0 in Grand Slam competition.

Azarenka is a two- time Aussie Open champ and two-time U.S. open runner-up to Williams.

The Belarusian Azarenka reached the French semis in her last trip to Paris in 2013.

Also on Saturday, 10th-seeded German Andrea Petkovic will be opposed by 17th- seeded former Roland Garros runner-up Sara Errani of Italy and 16th-seeded rising American Madison Keys will square off against 23rd-seeded fellow young gun Timea Bacsinszky of Switzerland.