The Spaniard was beaten in three sets after being blown away by her French opponent in the opening stages.

Muguruza took only 15 points in the first set as the Frenchwoman cruised to a 6-1 lead.

She recovered to take the second 3-6 but Mladenovic, the tournament's 13th seed, secured her place in the quarter-finals by taking the third set 6-3.

Muguruza's defeat means that only three of the top 10 seeds in the women's event are still in the draw.

Mladenovic is ow now face Timea Bacsinzky in the last eight after the Swiss came from a set down to beat Venus Williams of the United States, the 2002 French Open champion, 5-7, 6-2, 6-1.

Former world number one Caroline Wozniacki also moved into the quarter-finals with a 6-1, 4-6, 6-2 win over Russia's Svetlana Kuznetsova.

Elina Svitolina of Ukraine is also through after overcoming Poland's Magda Linette 6-4, 7-5.

The Czech Republic's Karolina Pliskova, seeded second, beat Carina Witthöft of Germany 7-5, 6-1.

In the men's draw, Rafael Nadal continued his emphatic form at Roland Garros with a straight sets win over fellow Spaniard Roberto Bautista Agut.

Nadal, attempting to become the first man to win 10 titles at a single Grand Slam event, reached the quarter-finals with a 6-1, 6-2, 6-2 win.

Awaiting Nadal in the last eight is another Spanish player, Pablo Carreno Busta.

Carreno Busta reached his first Grand Slam quarter-final with a 4-6, 7-6, 6-7, 6-4, 8-6 win over Canada's Milos Raonic, last year's Wimbledon runner-up.

Reigning champion Novak Djokovic of Serbia is also through after beating Albert Ramos-Vinolas of Spain 7-6, 6-1, 6-3.

He is now scheduled to face Austria's rising star Dominic Thiem, also safely through after recording a 6-1, 6-3, 6-1 win against Horacio Zeballos of Argentina.

Japan's Kei Nishikori required five sets to beat Hyeon Chung of South Korea 7-5, 6-4, 6-7, 0-6, 6-4 in a third-round match after rain halted play last night.

American Josh Isner was knocked out by Russia's Karen Khachanov of Russia 7-6, 6-3, 6-7, 7-6.

The 21-year-old is now set to face Britain's world number one Sir Andy Murray tomorrow.