Time to switch gears in Paris. Week two beckons, and the draw has been whittled down to sweet sixteen! We preview the bottom-half matchups at WTATennis.com

Sunday, Round of 16

[2] Agnieszka Radwanska (POL #2) vs. Tsvetana Pironkova (BUL #102)
Head-to-head: Radwanska leads, 9-2
Key Stat: Radwanska has won all three of the pair’s meetings on clay.

Two players not known as clay gurus will vie for a spot in the quarterfinals as they contest their 12th career meeting in Paris on Day 8. A hundred ranking spots separate Agnieszka Radwanska and Tsvetana Pironkova, but that rankings chasm might be misleading because both are executing some of their best clay-court tennis on the terre battue this week. Pironkova has taken out two Top 20 seeds in week one, and was in scintillating form on Friday as she thumped No.19-seeded Sloane Stephens, 6-2, 6-1, to reach the Round of 16 at Roland Garros for the first time. But it is Radwanska who has held the edge in the pair’s head-to-head, winning all three of their encounters on clay, and nine of eleven overall. “Well, we played so many times, but I think the last one was also quite some time ago,” Radwanska said of the Bulgarian. “Against her it’s always a good challenge. She’s really tricky opponent. You know, I expect a tough one as well.”

Pick: Radwanska in three

[4] Garbiñe Muguruza (ESP #4) vs. [13] Svetlana Kuznetsova (RUS #15)
Head-to-head: Kuznetsova leads, 1-0
Key Stat: Kuznetsova (49-12) will bid for her 50th Roland Garros win on Sunday.

One of the more heavily anticipated fourth-round clashes in Paris pits 2009 champion Svetlana Kuznetsova against No.4-seeded Garbiñe Muguruza. Both are rounding into form on the red clay, and both are loose ahead of this high-stakes contest. “I just want to go out there and just try to play my game,” Kuznetsova said after defeating Anastasia Pavlyuchenkova in round three. “Since I got a bit better ranking and everything I start to be tense again, and I don’t want it to happen.” Muguruza is taking a similar approach as she prepares to meet Kuznetsova for the second time. “I have a new mindset,” she said. “I’m not thinking of what I did last year, because every time I come to a tournament, no one remembers. People remember who plays good last year, but no one cares. Let’s see who is going to win this year, let’s see who is playing well.”

Pick: Muguruza in three

[6] Simona Halep (ROU #6) vs. [21] Sam Stosur (AUS #24)
Head-to-head: Halep leads, 4-3
Key Stat: Stosur owns a 2-0 edge over Halep at Roland Garros

An injured left wrist has done nothing to slow former runner-up Sam Stosur down in Paris. Will Simona Halep, another former Roland Garros runner-up and the player who absolutely thumped Stosur in Madrid a few weeks back, be able to do it? Maybe yes, maybe no. Either way, the Aussie is not going to carry the baggage from that shellacking into her eighth career meeting with the Romanian. “I’m not going to lose too much sleep over that match going into this next one in a couple days’ time,” Stosur said confidently after squeaking past Lucie Safarova on Day 6. That said, the Aussie knows she’s up against a daunting foe in Halep. When asked what makes Halep such a tough competitor, Stosur was quick with her answer. “I think her ability to continually put you in positions that you don’t necessarily want to be in,” she said. “She’s very consistent. She moves very well. She doesn’t have a big serve but she places it well. So she’s a player that you have to beat. She doesn’t really give too much away.”

Pick: Stosur in three

[25] Irina-Camelia Begu (ROU #28) vs. Shelby Rogers (USA #108)
Head-to-head: First Meeting
Key Stat: This is the first time that two Romanians (Halep, Begu) have reached the Round of 16 at Roland Garros since 1997.

The dream became the reality for 23-year-old American Shelby Rogers on Friday as she stunned No.10-seeded Petra Kvitova to reach the Round of 16 at a major for the first time. “There was a lot of noise and a lot of applause, and a lot of emotions taking over,” Rogers said of the experience. “I immediately started crying, and it was a very incredible moment.” Sunday’s challenge? Rebooting emotionally so that she may handle the task of facing rising Romanian Irina-Camelia Begu. The Bucharest-born 25-year-old is knocking on the door of the Top 20 and has been in great form on the clay, reaching the semifinals in Rome and earning wins over Victoria Azarenka (Rome) and Garbiñe Muguruza (Madrid) this spring. Will Rogers’ wild ride continue, or is it time for Begu to make her mark?

Pick: Begu in two

By the Numbers:

8 – Number of players to have reached the Roland Garros quarterfinals while ranked outside the Top 100 since 1983. Shelby Rogers and Tsvetana Pironkova will bid to become the ninth and tenth today.

4 – Number of former Grand Slam champions to reach the Round of 16 at Roland Garros this year (Kuznetsova, Stosur, Serena Williams and Venus Williams).

4-4 – Stosur’s record against the Top 10 at Roland Garros, which includes a victory over No.1 Serena Williams in 2010.

1 – Agnieszka Radwanska could attain the No.1 ranking at week’s end if she wins the title and Serena Williams does not reach the final.

– Chris Oddo, wtatennis.com contributor