Britain's Johanna Konta produced another terrific performance to beat Russian Ekaterina Makarova and set up an Australian Open quarter-final against Serena Williams.
Konta, seeded ninth, saw off 30th seed Makarova 6-1 6-4 to reach the last eight without dropping a set.
The Briton made her first Grand Slam semi-final in Melbourne last year.
Second seed Williams overcame stern resistance from Czech 16th seed Barbora Strycova to win 7-5 6-4.
Asked about facing the 22-time Grand Slam champion for the first time, Konta said: "Believe it or not that's an incredible experience for me.
"She's one of the few players still playing who I watched growing up.