World No. 1 Ash Barty delighted the home fans on Australia Day as she defeated Alison Riske 6-3 1-6 6-4 in a topsy-turvy fourth-round encounter at the Australian Open. Opening up the evening session on Rod Laver Arena, Barty came out of the blocks quickly to justify her status as a likely winner of the title in Melbourne. But Riske, the world No. 19, battled back gamely to level up with a 6-1 second set. Riske also took the opening game of the third set but Barty upped her level, rolling off four games in a row to take command of the fourth-round encounter. Riske rallied to 4-4 but Barty steeled herself to get within a game of victory, forcing Riske to serve to stay in the match – which she could not do, ending the match on a double fault. Barty now faces Petra Kvitova in a repeat of last year's quarter-final in Melbourne, which the Czech won. However, Barty has since beaten her three times and hopes to eke out another win to excite the home fans. "I love Petra but let's hope she doesn't break my heart on Tuesday," she said in her on-court interview. "It's been an incredible year for me, the past 12 months has been amazing, I'm just excited that I get another opportunity in a quarter-final of a Grand Slam – you don't get those every week so I'm really excited. "It was very tough with different ends playing very differently, I had to hang in there and give myself a chance."