Top seed and home hope Ashleigh Barty survived a scare to battle into the Australian Open quarter-finals in three sets on Sunday. The world number one beat American 18th seed Alison Riske 6-3, 1-6, 6-4 and next plays two-time Wimbledon champion Petra Kvitova, her opponent at the same stage last year. Kvitova won on that occasion and Barty will be out for revenge, after she avoided becoming the latest big name to exit. Six of the top 10 women's seeds are already out. "It was third time the charm for me last week and it was third time tonight as well," said the 23-year-old, who also needed three sets to beat Ukraine's Lesia Tsurenko in the first round.
"I just had to hang in there and try and give myself a chance."
On a day of celebrations for Australia Day, Barty got in the party mood by searing into an early 3-0 lead at a capacity 15,000 Rod Laver Arena.
Barty, named Young Australian of the Year on Saturday, was broken by the 29-year-old Riske but wasted little time in hitting back for a 4-2 lead.
Barty nailed the first set in 34 minutes on her second set point when Riske -- dumped out in the first round last year in Melbourne -- shot weakly into the net.
The American had beaten Barty in both their previous meetings, the latest coming at Wimbledon in the fourth round last year.
And the crowd fell quiet in the second set as Barty -- who once gave up tennis for professional cricket -- racked up 12 unforced errors.
Riske, whose previous best Grand Slam performance was reaching the quarter-finals at Wimbledon last year, wrapped up the second set in 27 minutes to leave Rod Laver Arena stunned.
They went to a decider and it was the French Open champion Barty who drew first blood, breaking for a 3-1 lead, but Riske broke back when the Australian planted a backhand wide.
Barty, unflappable in her title charge up until now, kept making errors.
She put a straightforward forehand long and Riske was level again at 4-4.
Barty then gathered herself to hold serve. Riske was serving to stay in the tournament -- and she lost her nerve at the fatal moment, gifting Barty victory with a double-fault on match point.
There is immense pressure on Barty to become the first Australian woman since Chris O'Neil in 1978 to win their home Grand Slam.
The draw has opened up nicely for Barty with reigning champion Naomi Osaka, record-chasing Serena Williams and second seed Karolina Pliskova all going out in round three.