First British last eight duo for four decades
Andy Murray dealt with a potentially tricky challenge in the Rod Laver Arena to beat another home favourite, seeing off Bernard Tomic 6-4 6-4 7-6 (7/4).
Johanna Konta became the first British woman to reach a Grand Slam quarter-final for 32 years by beating Ekaterina Makarova.
Murray, the world number two, will play eighth seed David Ferrer for a place in the semi finals, after the Spaniard knocked out John Isner in straight sets.
Murray leads Ferrer 12-6 in head-to-head matches, with the Scot winning the last five.
Konta, making her debut in the main draw, fought back to beat the 21st seed 4-6 6-4 8-6 in the fourth round.
The last British woman to play in the quarter-finals of a Grand Slam was Jo Durie, at Wimbledon in 1984.
Sue Barker, Robin Drysdale and John Lloyd all reached the quarter-finals of the Australian Open in 1977.