French Open PHOTOS: Azarenka, Sharapova, Nadal through

Third seed Victoria Azarenka stuttered into the last 16 of the French Open but her title credentials were given a rigorous examination in a 4-6, 6-3, 6-1 win over a spirited Alize Cornet on Saturday.

Kei Nishikori became the first Japanese man to reach the last 16 of the French Open in 75 years when he beat French 24th seed Benoit Paire 6-3, 6-7(3), 6-4, 6-1 in the third round on Saturday.

Nishikori, the 13th seed, kept his composure despite his opponent's histrionics and bad temper, weathering the fickle Court Suzanne Lenglen crowd to prevail on his first match point.

Fumiteru Nakano was the last man to reach the last 16 at Roland Garros, in 1938.

Nishikori, whose best Grand-Slam result is a 2012 Australian Open quarter-final, will next face either seven-times champion Rafael Nadal of Spain or Italian 27th seed Fabio Fognini.

Former champion Francesca Schiavone produced an attention-grabbing display of claycourt tennis to advance into the fourth round of the French Open with a 6-2, 6-1 annihilation of French 13th seed Marion Bartoli on Saturday.

With all eyes on defending champion Maria Sharapova and world number one Serena Williams, Italian Schiavone, the 2010 Roland Garros winner, had gone unnoticed until she ended Bartoli's run in ruthless fashion on Court Suzanne Lenglen.

Bartoli fought until the end but there was little she could do against Schiavone's repertoire of sliced backhands, spinning forehands and cunning lobs that got the better of the Frenchwoman after 78 minutes.

Defending champion Maria Sharapova was pushed for the first time at the French Open before overcoming tenacious Chinese player Zheng Jie 6-1, 7-5 on Chatrier Court on Saturday.

The Russian second seed, playing for the third day in succession after needing two days to complete her second round because of rain, was forced into a scrap after initially looking a class above her 43rd-ranked opponent.

Sharapova trailed 4-1 in the second set, clawed back to 4-4, then fell 5-4 behind with Zheng serving to level the match but turned up the volume of her grunting and her play to avoid being extended further.

The 26-year-old wrapped up victory when Zheng netted a forehand service return, moving through to a last-16 clash against American Sloane Stephens.

Seven-times champion Rafael Nadal held off a brave yet sporadic challenge from Italian Fabio Fognini 7-6(5), 6-4, 6-4 to book his place in the fourth round of the French Open on Saturday.

Third seed Nadal suffered the occasional wobble but, for the first time this year, did not drop a set as he set up a meeting with Japanese 13th seed Kei Nishikori on his 27th birthday on Monday.

The Spaniard, who struggled in his first two rounds, was bothered by Fognini's clever shots early on but once he got the measure of the 27th seed the contest was effectively over.

Nadal, who has 11 grand-slam titles to his name, sealed the win after two hours 45 minutes when Fognini sent a backhand long.

"I think he is a fantastic player," Nadal said of his opponent in a courtside interview.

"Winning the first set is always important especially after losing it in the first matches."

Nadal's ability to play the important points as if they were a matter of life and death made the difference against Fognini. The Italian entered Court Philippe Chatrier with a swagger but the smile was wiped off his face eventually.

Fognini looked the more aggressive player at the start and broke for 3-2 after sending Nadal left and right, finishing off a long rally with a routine smash.

His sudden backhand accelerations caused the Spaniard problems but Nadal broke back for 4-4 when his opponent netted an easy forehand.

He had three set points in the 10th game, only for Fognini to coolly see them off - one with a stunning forehand winner.

The Italian broke in the following game when Nadal sent a forehand long but the muscular Spaniard broke back to force a tiebreak.

Nadal, facing the prospect of losing the opening set in the first three rounds at Roland Garros for the first time, won an epic, lung-burning point after Fognini was caught off guard by his opponent's back spin to open up a 5-4 lead in the decider.

Nadal then had the upper hand, to Fognini's frustration.