Updated

Madrid, Spain (SportsNetwork.com) - Australian Open champion Li Na and last year's Madrid runner-up Maria Sharapova were a pair of second-round winners Tuesday at the $4.2 million Madrid Open.

The second-seeded Chinese star Li leveled fellow countrywoman Zheng Jie for a fourth straight time, 6-2, 6-3, while the eighth-seeded former world No. 1 Sharapova got past 56th-ranked American Christina McHale 6-1, 4-6, 6-4 on the red clay at the Magic Box.

Sharapova had to rally in the third set, which she trailed 4-1 before winning five straight games on Day 4.

"After a really good start I didn't keep that level. I didn't keep doing what I was doing. I think I had a bit of a letdown," Sharapova said.

The recent Stuttgart titlist Sharapova lost to Serena Williams in last year's Madrid and French Open finals. Her third-round opponent will be former U.S. Open champion and former French Open runner-up Samantha Stosur.

Meanwhile, fifth-seeded Czech slugger and 2011 Madrid champion Petra Kvitova fought back to beat American Varvara Lepchenko 2-6, 6-2, 6-1, 10th-seeded former French Open runner-up Sara Errani dropped former Roland Garros champion and fellow Italian Francesca Schiavone 6-3, 6-1 and No. 11 seed Ana Ivanovic cruised to a 6-4, 6-2 decision over fellow Serb Bojana Jovanovski.

Also on Tuesday, 16th-seeded American Sloane Stephens outlasted Czech qualifier Petra Cetkovska 6-4, 2-6, 6-3, Czech Lucie Safarova subdued Slovak Magdalena Rybarikova 6-1, 6-2 and Stosur edged out Spaniard Garbine Muguruza 7-5, 3-6, 6-1. Stephens is rewarded with a third-round match against Li.

On Wednesday, the world No. 1 and two-time reigning Madrid champion Williams will take on Chinese Peng Shuai.

Also taking to the courts Wednesday will be the likes of third-seeded Agnieszka Radwanska and former No. 1 stars Jelena Jankovic and Caroline Wozniacki, who was a Madrid runner-up in 2009.