French Open champion Anastasia Myskina and compatriot Elena Dementieva were dumped out of the Australian Open on Monday.

Nathalie Dechy of France upset Russian third seed Myskina 6-4, 6-2 while Switzerland's Patty Schnyder fought back to upset Dementieva 6-7, 7-6, 6-2 to reach the quarter-finals.

Through to her first Grand Slam quarter-final at her 37th attempt, Dechy held her nerve as Myskina's game fell apart on the centre court.

Myskina one of the favourites to win in Melbourne, made an embarrassing 45 unforced errors to contribute to her defeat.

Seeded 19th, Dechy set up a clash against Schynder in the quarter-finals on Wednesday.

The Swiss left-hander proved too consistent for the Russian, who struggled to hold her serve and was troubled by a blister on her toe, in a marathon match lasting almost three hours on Rod Laver Arena centre court.

The momentum clearly shifted in Schnyder's favour after she claimed the second-set tie-breaker 7-4.

Dementieva, runner-up at the French and U.S. Opens last year, gave Schnyder her third match point with a double fault and then lamely netted a volley.

Schnyder, who made the semi-finals last year in a career-best performance, will play either third-seeded Russian Anastasia Myskina or 19th seed Nathalie Dechy of France in the last eight.