Australian Open: Day 8 in Melbourne

The Williams sisters made it through to the last eight while Stanislas Wawrinka also stayed in contention to defend his title.(AP/AFP Photos)

Venus Williams' strong run at the Australian Open continued on Monday when she beat sixth-seeded Agnieszka Radwanska 6-3, 2-6, 6-1 to reach a Grand Slam quarterfinal for the first time since 2010.

Top seed Serena Williams came from a set down to beat 24th seed Garbine Muguruza 2-6, 6-3, 6-2 to set up a final-eight clash with last year's finalist Dominika Cibulkova of Slovakia, seeded 11.

Unseeded Victoria Azarenka lost 2-6, 6-3, 3-6 against 11th seed an last year's finalist Dominika Cibulkova of Slovakia.

Defending champion fourth seed Stan Wawrinka prevailed 7-6, 6-4, 4-6, 7-6 over Spain's Guillermo Garcia-Lopez.

Fifth Seed Kei Nishikori beat Spain's David Ferrer 6-3, 6-3, 6-3 to storm into quarters where he faces defending champion Stan Wawrinka.

Milos Raonic, who thundered down 30 aces in his five-set win over Feliciano Lopez, became the first Canadian man to reach the Australian Open quarter-finals in 47 years.