Serena Williams knocked out of French Open

PARIS: Defending champion Serena Williams followed her sister Venus out of the French Open on a dramatic fourth day.

Serena lost 6-2 6-2 to Spain's Garbine Muguruza after Venus had earlier been beaten 2-6 6-3 6-4 by Slovakian Anna Schmiedlova at Roland Garros.

It is the first time in her career that Serena has failed to reach the second week of a Grand Slam as the top seed.

It means a projected third-round clash between the Williams sisters will now feature Muguruza and Schmiedlova.

Muguruza, 20, took full advantage of a very out-of-sorts Serena Williams on a cool and breezy Court Suzanne Lenglen.

The 32-year-old American made 29 errors and just eight winners in a 64-minute defeat that means she will not add to her 17 Grand Slam titles this fortnight.

She looked inexplicably underpowered as her usually mighty serve failed to win enough free points and the rest of her game disintegrated.

There was a brief moment of hope for her coach Patrick Mouratoglou in the stands when his charge got a break back at 3-1 down in the second set, but a dreadful service game followed as she was broken for the fourth time to love.

The world number one looked as bemused as those watching, shaking her head and looking to the sky, while Muguruza remained impressively calm at the other end of the court.

The Venezuelan-born Barcelona resident recovered from 0-40 to move 5-1 ahead, as dark clouds gathered, and Muguruza coolly served out her first ever win over a top-five player to love.

Venus Williams, 33, had earlier made a strong start before losing eight of nine games on her way to defeat against 19-year-old Schmiedlova on Court Philippe Chatrier.