Kvitova powers through

Paris 

 Wimbledon champion Petra Kvitova powered into the last 16 at the French Open yesterday after early round struggles at Roland Garros, while Sloane Stephens revived flagging American hopes.

Kvitova, the fourth seed from the Czech Republic, finally found her form to outplay Romanian Irina-Camelia Begu 6-3, 6-2 in just 58 minutes, taking the last five games at a canter.

That was in stark contrast to her first two rounds that saw her grind out six sets and spend just four minutes short of five hours on the court.

"I think it was for sure the best match which I played here so far, so I'm really glad for it," Kvitova said.

"I'm glad that I didn't forget many things from my game and it's still there. I felt better today, for sure. It's the third round which I didn't pass here last year, so I was really motivated by it."

Next up for Kvitova, who also won Wimbledon in 2011, but who has only managed a single semi-final in Paris in 2012, will be a fourth round tie against Timea Bacsinszky of Switzerland who upset 16th seeded American Madison Keys 6-4, 6-2.

Stephens, clawing her way back up the world rankings after a bad wrist injury sidelined her late last year, saw off Bulgaria's Tsevtana Pironkova 6-4, 6-1, winning eight of the last nine games to clinch the victory.

Her reward for that is likely to be a fourth round clash with top seed and compatriot Serena Williams.