Ana will play Russian Nadia Petrova for a semi-final place.
Nadia Petrova made her breakthrough at the French Open two years ago when she defeated Monica Seles and Jennifer Capriati on a run to the semi-finals.
Ana beat Petrova in their only previous encounter. That came in Miami at the start of the year when Ana won 6-4, 7-5.
Ana's match will be first on Suzanne Lenglen Court.
Ana continued her surprise run at the French Open with a fourth-round victory over Francesca Schiavone on Monday.
Ana, who ended the hopes of home favourite Amelie Mauresmo in the previous round, recorded a narrow 6-4 6-7 (3/7) 6-3 victory on Court Two at Roland Garros.
Ana took the first set 6-4 in 41 minutes but Schiavone, at 22 the higher seed by seven places, moved ahead in the second as she looked to get back in the match.
Schiavone, troubled by a total of eight double faults, served for the set but failed in her task and so into the tie-break they went.
She showed grace under pressure ... and many other kind messages are left for Ana on this site.
Thank you all. There is a new entry in the Diary section where Ana thanks you personally.
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When Ana Ivanovic won her first career title as a qualifier in Canberra in January, she was tipped by many as a future star of the women's game.
On Saturday, the 17-year-old from Serbia and Montenegro proved she has the nerve for the big stage when she broke French hearts with a 6-4 3-6 6-4 victory over third seed Amelie Mauresmo in the third round of the French Open.
"It was one of the best matches I've played," Ivanovic said. "Maybe not the best but still I'm really happy that I took my opportunities and I look forward to the next matches."
Amelie Mauresmo again cracked under pressure at the French Open when Ana beat her 6-4 3-6 6-4 in a third-round match on Saturday.
Mauresmo, who has never got past the quarter-finals at her home event, started nervously but gave the impression she would recover, fighting back from 3-1 down to take the second set.
The Frenchwoman, who was let down by her usually reliable serve, was broken again in the fourth game of the decisive set.
Ana kept her composure before a partisan crowd until Mauresmo bowed out with a double fault on the first match point.
Ana and Nenad Zimonjic won their first round mixed doubles match against number two seeds Ai Sugiyama (JPN) and Max Mirnyi (BLR) 6-3,3-6,10-8.
Ana entered the mixed doubles draw as well, paired with Nenad Zimonjic. Their first match is later today against number two seeds Ai Sugiyama (JPN)/Max Mirnyi (BLR).
Ana and her partner Tina Krizan lost their first round doubles match today to Stephanie Cohen-Aloro (FRA) and Selima Sfar (TUN), 6-4 6-2.
Ana clinched a place in the third round with a superb 6-3, 6-1 victory over Iveta Benesova of Czech republic.
All she needed was 53 minutes(originally posted by Dasha on www.ana-ivanovic.com)
In the first set Ana had 12 winners (including service), 16 unforced errors and two double faults. Ana made two breaks, and lost one service game.
In the second set, the number off winners and unforced errors was the same - ten. Ana had only one double fault, and three breaks off serve.
Ana made short work of world number 103 Stephanie Foretz as she eased into round two of the French Open in Paris on Tuesday. The French was out of her depth against 29th seed Ana.
Ana will play Iveta Benesova of Chech republic for a place in the last 32.
