Ana Ivanovic is made to work harder than expected but finally sees off 17-year-old Dane Caroline Wozniacki 6-1 7-6 (7-2)

Venus Williams is also stretched in her fourth-round match before beating Poland's Marta Domachowska 6-4 6-4

Poland's Agnieszka Radwanska, the 29th seed, continues her fine run with a 1-6 7-5 6-0 win over 14th seed Nadia Petrova

Russian 27th seed Maria Kirilenko makes a strong start to her first Grand Slam quarter-final against Daniela Hantuchova

Hantuchova battles back from a set and a break down to win 1-6 6-4 6-4

A rejuvenated James Blake sweeps into the last eight with a quickfire 6-3 6-4 6-4 defeat of Marin Cilic

Roger Federer returns to action after his epic on Saturday and has another tough time against Tomas Berdych

Berdych has his chances but cannot convert two set points in the second set tie-break

Federer makes Berdych pay by finding his best form to win 6-4 7-6 (9-7) 6-3 and reach the last eight

David Ferrer is happy after beating Juan Carlos Ferrerro to reach the quarter-finals in Melbourne for the first time

But being beaten by his fellow Spaniard is all too much for former French Open champion Juan Carlos Ferrero

Out in support of Lleyton Hewitt are Australian A-listers actress Nicole Kidman and singing husband Keith Urban

Lleyton Hewitt loses a tight first set against Novak Djokovic but the battling Aussie number one isn't throwing in the towel

Hewitt saves two match points but is broken in his next game, losing in three sets for the first time at the Aussie Open

Novak Djokovic takes his fast and powerful serving game through to the quarters to meet fifth seed David Ferrer